US President Barack Obama said Thursday that he envisioned greater defense cooperation with Australia in a tension-filled Asia, welcoming Prime Minister Tony Abbott despite differences on climate change.

In the conservative leader's first White House summit since his election in September, Abbott said that Australia "will be an utterly indispensable ally" of the United States and welcomed Obama's efforts to shift more US attention on Asia.

Obama praised Abbott for increasing Australia's defense budget in tough economic times, calling the move a recognition that "we all have to make sure that we're doing our fair share to help maintain global order and security."

"We don't have a better friend in the world, as well as the Asia-Pacific region, than Australia," Obama told reporters after the Oval Office meeting.

Obama agreed with Australia's previous government to send some 2,500 US Marines by 2016-2017 to the northern city of Darwin, which lies strategically close to hotspots in Southeast Asia.

Obama said that the United States and Australia have since then worked out force postures "that will enhance the bilateral cooperation between our militaries and give us additional reach throughout this very important part of the world."

A White House statement said that the United States and Australia were looking to expand cooperation in "maritime capacity building" and humanitarian relief in Asia.

- Differences on climate change -

Obama called Australia "one of my favorite countries to visit" and said he looked forward to traveling to Brisbane in November for the summit of the Group of 20 major economies.

But Abbott, who comes from the opposite end of the political spectrum, has previously resisted calls by the Obama administration to make climate change a top priority at the summit.

Obama just last week laid out his most ambitious plan yet to reduce carbon emissions blamed for climate change.

Abbott has called the science behind climate change "absolute crap" and moved to undo environmental policies of his predecessor Kevin Rudd, who was one of Obama's closest international allies.

Obama raised climate change in the meeting and wants the issue to be on the agenda in Brisbane, White House press secretary Jay Carney said.

The White House statement said that the United States and Australia "recognize the pressing need to address climate change, a serious issue that requires a strong and effective international response."

The Intergovernmental Panel on Climate Change, a UN-led scientific panel, has warned that polluters need to make major, urgent cuts in carbon emissions if the planet is to reduce worst-case consequences such as rising sea levels, drought and more frequent disasters.

- Enforcing 'rules' in Asia -

The US-Australia summit comes amid growing tensions in Asia, with Japan, the Philippines and Vietnam accusing China of increasingly assertive moves on maritime disputes.

Obama and Abbott both said that they embraced China's rise but would hold firm on principles. Obama said it was important for a growing China to "abide by basic international law and norms."

Abbott, speaking earlier at the US Chamber of Commerce, said that Australia sought close relations with countries throughout Asia, including frequent rivals Japan and China.

"It helps that, in most circumstances, Australia is strong enough to be useful but not big enough to be threatening," Abbott said.

"I am confident that the coming century will indeed be the Asian century, but only if America is there too to keep the peace and enforce the rules," Abbott said.