Washington: With reports suggesting a deteriorating situation in Syria, three leading Senators have demanded a US-led military intervention in the country, with or without a UN approval, arguing that it was necessary to save thousands of lives.

Senators John McCain, Joe Lieberman and Lindsay Graham said the only realistic way to stop the "slaughter" in Syria and save innocent lives is to do so with foreign airpower.

And for this no UN approval is required, they argued.

The Obama Administration, however, has ruled this out.

The Pentagon said intervention at this time could very well "exacerbate problems" inside the country.

"Providing military assistance to the Free Syrian Army and other opposition groups is necessary, but as (Bashar) Assad continues to intensify his assault, that alone will not be sufficient to stop the slaughter and save innocent lives. The only realistic way to do so is with foreign airpower," the three Senators said in a joint statement.

"Therefore, if requested by the Syrian National Council and the Free Syrian Army, the United States should help organise an international effort to protect civilian population centers in Syria through airstrikes on Assad's forces, the Senators said.

The Senators said any such intervention would include America's Arab partners such as Saudi Arabia, the UAE, Jordan, and Qatar, and "willing allies" in the EU and NATO, the most important being Turkey.

McCain, Lieberman and Graham said the ultimate goal of airstrikes should be to protect civilian population centers and establish safe havens in which opposition forces can organise, rest, refit, and plan their political and military activities against Assad.

"These safe havens could serve as platforms for the delivery of humanitarian and military assistance – including weapons and ammunition, body armour and other personal protective equipment, tactical intelligence, secure communications equipment, food and water, and medical supplies," they said.

"These safe havens could also help the Free Syrian Army and other armed groups in Syria to train and organize themselves into more cohesive and effective military forces, likely with the assistance of foreign partners, and provide political space for the Syrian National Council to organise on Syrian soil," the Senators wrote.

The three Senators argued that there will be "no UN Security Council mandate" for such an operation, noting that Russia and China took that option off the table long ago.

"But let's not forget: NATO took military action to save Kosovo in 1999 without formal UN authorisation. There is no reason why the Arab League, the Gulf Cooperation Council (GCC), or NATO, or a leading coalition within the Friends of Syria contact group, or all of them speaking in unison, could not provide international legitimacy for military measures to save Syria today," they said.

(Agencies)