"Evidence indicates that the plane was shot down by a surface-to-air missile that was launched from an area controlled by Russia-backed separatists inside of Ukraine," he said. "It's too early to guess what the intentions of those who launched these missiles. What we know right now, that a surface to air missile was fired. The shot was taken within the territory that is under the control of the separatists," US President said, adding that US is talking to the international community on this issue. Read More: Interpol teams to help identify MH17 victims MH17 disaster wipes out entire Malaysian family of six (JPN/Agencies)
Obama, who spoke with his Russian counterpart Vladimir Putin, blamed Russia for the incident, saying that Russia provided sophisticated surface-to-air missiles to the Ukrainian separatists.
"He (Putin) has the most control over the situation. He has certainly not exercised (that)," Obama said.
"We also know that this is not the first time a plane has been shot down in eastern Ukraine. Over the last several weeks Russian-backed separatists have shot down a Ukrainian transport plane and a Ukrainian helicopter, and they claimed responsibility for shooting down a Ukrainian fighter jet. Moreover, we know that these separatists have received a steady flow of support from Russia," he said.
Noting that this is a wakeup call for the international community, Obama warned that this tragic event would have consequences.
Describing the death of nearly 300 people on board the plane as an outrage of unspeakable proportions, Obama said, "Our thoughts and prayers are with his family for this terrible loss."
"This was a global tragedy. So there has to be a credible international investigation into what happened. The UN Security Council has endorsed this investigation, and we will hold all its members, including Russia, to their word," he added.
He also called for an immediate ceasefire between separatist and the government in Ukraine.
"In order to facilitate that investigation, Russia, pro-Russian separatists and Ukraine must adhere to an immediate cease-fire. Evidence must not be tampered with. Investigators need to access the crash site," Obama said.
Obama said that US is ready to provide any assistance that is necessary.
"We've already offered the support of the FBI and the National Transportation Safety Board, which has experience in working with international partners on these types of investigations. They are on their way, personnel from the FBI and the National Transportation Safety Board," he noted.
The President said this outrageous event underscores that it is time for peace and security to be restored in Ukraine.
"For months we've supported a pathway to peace, and the Ukrainian government has reached out to all Ukrainians, put forward a peace plan and lived up to a cease-fire, despite repeated violations by the separatists, violations that took the lives of Ukrainian soldiers and personnel," he said.
Alleging that time and again, Russia has refused to take the concrete steps necessary to de-escalate the situation, Obama said he spoke to Putin on Thursday in the wake of additional sanctions that US has imposed.
"He said he wasn't happy with them, and I told him that we have been very clear from the outset that we want Russia to take the path that would result in peace in Ukraine, but so far, at least, Russia has failed to take that path,” he said.
"Instead, it has continued to violate Ukrainian sovereignty and to support violent separatists. It has also failed to use its influence to press the separatists to abide by a cease-fire. That's why, together with our allies, we've imposed growing costs on Russia," he added.
Obama said violence and conflict inevitably lead to unforeseen consequences.
"Russia, these separatists, and Ukraine all have the capacity to put an end to the fighting. Meanwhile, the United States is going to continue to lead efforts within the world community to de-escalate the situation, to stand up for the sovereignty and territorial integrity of Ukraine and to support the people of Ukraine as they courageously work to strengthen their democracy and make their own decisions about how they should move forward," he said.
Obama said he made it clear to Putin that his preferred path is to resolve this diplomatically.
"But that means that he and the Russian government have to make a strategic decision. Are they going to continue to support violent separatists whose intent is to undermine the government of Ukraine, or are they prepared to work with the government of Ukraine to arrive at a cease-fire and a peace that takes into account the interests of all Ukrainians?" he asked.
"There has been some improved language at times over the last month coming from the Kremlin and coming from President Putin, but what we have not seen is an actual transition and different actions that would give us confidence that that's the direction that they want to take," he said.
"We will continue to make clear that as Russia engages in efforts that are supporting the separatists, that we have a capacity to increase the costs that we impose on them, and we will do so -- not because we're interested in hurting Russia for the sake of hurting Russia, but because we believe in standing up for the basic principle that a country's sovereignty and territorial integrity has to be respected, and it is not the United States, or Russia, or Germany, or any other country that should be deciding what happens in that country," Obama said.
The plane had 100 researchers and advocates traveling to an international conference in Australia dedicated to combating AIDS/HIV, Obama said.
"On board Malaysian Airlines Flight MH-17 there were apparently near 100 researchers and advocates traveling to an international conference in Australia dedicated to combating AIDS/HIV," he said.
"These were men and women who had dedicated their own lives to saving the lives of others, and they were taken from us in a senseless act of violence," he said.
At least one American citizen was also killed in the tragic incident, which Obama said was a result of a surface to air missile hitting the Malaysian plane.
"Because events are moving so quickly, I don't want to say with absolute certainty that there might not be additional Americans, but at this stage, having worked through the list, been in contact with the Malaysian government, which processed the passports as folks were boarding. This is our best assessment of the number of Americans that were killed," he said.
"Obviously, that does nothing to lessen our outrage about all those families, regardless of nationality. It is a heartbreaking event," Obama said.
Obama reaches out to global leaders for investigation
After blaming pro-Russia Ukrainian rebels for the shooting down of a Malaysia Airlines plane that killed nearly 300 people, US President Barack Obama has called on his counterparts seeking an impartial international investigation into the accident.
“In separate phone calls with the US President, British Prime Minister David Cameroon; German Chancellor Angela Merkel; and Australian Prime Minister Tony Abbott, agreed on a prompt, full, unimpeded and transparent international investigation,” the White House said in a statement.
"They (Obama and Merkel) reaffirmed that all parties must guarantee international investigators full, secure, and unfettered access to the incident site to conduct a thorough and credible investigation without delay. They also noted the necessity of all evidence remaining intact and in Ukraine," it said.
“Obama and Merkel discussed the latest information regarding the tragic downing of Malaysian plane,” it added.
Discussing the plane shoot-down, the White House said, Obama and Cameron agreed that an independent, full, credible, and unimpeded international investigation must begin immediately.
"They also agreed that all countries should do their utmost to ensure the Russian-supported separatists grant secure access to the site of the incident," the statement said.
"The two leaders discussed the recent steps taken by United States and the European Union to increase the costs to Russia, given its failure to take the concrete steps needed to de-escalate the situation, and reiterated the need to take further action if Russia continues to fail to take these steps," it said.
According to the White House, Obama expressed condolences on behalf of the American people to the Australian families who lost loved ones on board the flight.
"The two leaders discussed the importance of a prompt, full, unimpeded and transparent international investigation, and they stressed the need for immediate access by international investigators to the crash site," it said.
Obama underscored continuing US support and cooperation with Australia as this issue unfolds, and the two leaders committed to remaining in close touch moving forward, the White House said.
Separately, US Vice President Joe Biden called Ukrainian President Petro Poroshenko; and the Polish Prime Minister Donald Tusk to discuss the issue.
Biden and Tusk agreed that a prompt international investigation with safe and unimpeded access was the need of the hour.
The leaders also discussed the situation in eastern Ukraine, noting that Russia was supplying weapons and training, including anti-aircraft weapons – to the separatists, with profoundly de-stabilizing consequences.
An entire family of six persons that had been returning home after three years of living abroad was among the 44 Malaysians killed in the MH17 disaster, media reports said on Saturday.
Tambi Jiee, 49, and his wife Ariza Ghazalee, 46, perished along with their four children when the Malaysia Airlines flight went down in eastern Ukraine.
They were reportedly returning to Malaysia after her husband's three-year posting in Kazakhstan for energy giant Shell, first taking a short European holiday.
Images of a wailing Jamilah Noriah Abang Anuar, 72, Ariza's mother, dominated front pages of Malaysian dailies on Saturday.
"I lost my daughter and her family in a blink of an eye," the New Straits Times quoted her as saying from her home in the eastern Malaysian state of Sarawak on Borneo island.
Ariza had posted a photo on Facebook showing the family's luggage as they prepared to embark from Amsterdam's Schiphol airport for the flight to Kuala Lumpur.
"17 July 2014, starting our new hijrah (journey), Alhamdulillah (praise God)," read the accompanying message. Her son Afzal Tambi also posted his thanks and farewells to friends from Kazakhstan on Thursday.
"Before it gets too cheezy, I just want to thank everyone who made it bearable for me to live here and for sharing with me amazing memories to reminisce on," the message said.
The Boeing 777 came down with 298 onboard in a separatist-held region of Ukraine, with the United States claiming it was shot down in a missile attack, a possible casualty of the Kiev government's battle with pro-Russia rebels.
The disaster has deeply shocked Malaysia, which is still grappling with the trauma of the March 8 disappearance of
MH370 with 239 passengers and crew aboard.
No trace of the MH370 plane has been found, a mystery that has severely damaged Malaysia's image abroad and left furious passengers' relatives deeply anguished and demanding answers.
"Evidence indicates that the plane was shot down by a surface-to-air missile that was launched from an area controlled by Russia-backed separatists inside of Ukraine," he said.
"It's too early to guess what the intentions of those who launched these missiles. What we know right now, that a surface to air missile was fired. The shot was taken within the territory that is under the control of the separatists," US President said, adding that US is talking to the international community on this issue.
Read More: Interpol teams to help identify MH17 victims
MH17 disaster wipes out entire Malaysian family of six