Melbourne: US President Barack Obama is expected to meet Australian Prime Minister Julia Gillard on Wednesday as both sides are likely to discuss measures to strengthen defence ties and prospects of Canberra's role in Afghanistan after withdrawal of coalition forces in 2014.

Obama is set to arrive in Canberra Tuesday afternoon after twice-postponing his visit to update a 60-year-old security alliance with the country, a newspaper reported.
 The US president will be meeting Gillard in the evening and the two leaders are expected to discuss global economic risks, the prospects for a new Asia-Pacific trade deal and China's growing military prowess.

Australia's commitment to the Afghanistan conflict after 2014, when coalition forces are due to hand over security responsibility to Afghan forces, will also form the part of discussions.
It is said that a permanent US marines presence will be officially announced on Thursday in Darwin. Australia's role in the United States' Asia-Pacific military strategy will be covered by the leaders in their discussions.

With the growing concern about the rise of China, and particularly its use of satellites and cyber technology to penetrate nations' defence and commercial secrets, the two sides are also expected to deliberate on it.

The report also mentioned that foreign affairs experts were also expecting discussions over the threats posed by North Korea and Iran.
Lowy Institute senior fellow Andrew Shearer, a foreign policy adviser to former prime-minister John Howard, said the one-hour discussion between Obama and Gillard would have been carefully planned.
"The aim is to avoid unpleasant surprises," he said.
"That said, there is a high degree of frankness in those discussions, compared to some other meetings with world leaders," he said.
Shearer predicted the issues would focus on the key strategic challenges to both nations.

"I expect the bulk of the discussion will be around the big issues the two countries are working on together," he said.

Afghanistan will have to come up with planning towards the 2014 transition that Obama has talked about and how that effects Australia's contribution, he said.

"They will want to touch on the revelations about the Iranian nuclear program.
"Then there are a bundle of regional issues, including China and India after Ms Gillard's uranium announcement," he said.

"I imagine they'll touch on North Korea and then finally, they will coordinate positions for the coming East Asia Summit meeting in Bali," Shearer said.
Gillard could secure extra time with the President on Thursday, tipping they would travel to Darwin together on Air Force One, he said.
"It wouldn't surprise me if the Prime Minister flew out with the President. That's invaluable face time with the President, where you can have those private discussions," he said.