President Obama speaks to the media during a meeting with Julia Gillard, prime minister of Australia, in the Oval Office of the White House in Washington, D.C., March 7, 2011. (Olivier Douliery/VIA BLOOMBERG)

President Obama will touch down on Australian soil for the first time Wednesday morning for a whirlwind two-day visit that the administration will use to unveil an expanded military presence that is part of its shifting focus on security in the Asian Pacific region.

During a stop at a military facility in Darwin, in Australia's remote Northern Territory, Obama and Australian Prime Minister Julia Gillard are expected to announce a plan to allow U.S. Marines to use local bases for training and amphibious exercises.

White House aides declined Monday to provide details of the visit, but analysts cast the move as a modest first step as the United States reconsiders its “force posture” in a fast-changing region at a time when U.S. troops in Japan are undergoing a partial relocation to Guam.

In the face of growing Chinese economic and military power, U.S. allies across Asia have been asking for help in counterbalancing potential threats in the disputed South China Sea and elsewhere. Australia is located close to Southeast Asia, an area of economic growth and emerging economies that the United States would like to influence as political democracies.

Furthermore, analysts said, having access to military bases in Australia would allow the United States another staging area outside the range of China’s increasingly sophisticated ballistic missiles.

The plan is “part of a general idea about how to disperse military power away from a concentration in North Asia,” said Patrick Cronin, an Asia Pacific security analyst at the Center for a New American Security. “It’s a continuing concerted step over the past five years, when the Chinese rise has loomed larger as an issue than ever.”

Previewing Obama’s trip to Australia, Adm. Robert Willard, chief of the U.S. Pacific Command in Hawaii, said Sunday that placing resources near Southeast Asia also would allow the United States to respond to natural disasters that require massive humanitarian and military aid.

“Any opportunities that we have to locate forces in the Southeast Asia region relieves some pressure on that need to, at great expense, deploy and sustain forces present in Southeast Asia,” Willard said. “So any rebalancing that can take place over time to permit the United States to more effectively be present in the region, I think, is a positive step — and that includes South Asia as well.”

During his stay, Obama is scheduled to deliver an address to Australia’s Parliament in Canberra in what the White House is billing as his “anchor speech” to lay out his vision for an American presence in the region. Obama also will tour a military facility in Darwin, where he and Gillard are expected to announce the new partnership.

Close relationship

Obama and Gillard, who are both 50, have enjoyed a close working relationship since Obama played host to her in Washington and they toured a local high school. Twice before, Obama canceled scheduled visits to Australia — once in 2009 so he could remain in Washington for a vote on his health-care plan and again in 2010 after the Gulf of Mexico oil spill.

Despite that, Obama is still enormously popular in Australia, said Australia’s ambassador to the United States, Kim Beazley.

“He’ll arrive in a country that truly loves him,” Beazley said. “He represents what we think the U.S. has become. He speaks in a language easy to understand; his values are closer to the way . . . Australians see the world. Australians respect the United States, what the United States stands for. They respect what the United States does for the world.”

The public also is eager for U.S. defense commitments, said Fergus Hanson, a pollster and analyst at the Lowy Institute for International Policy, an influential Australian think tank. In a 2010 Lowy poll, 55 percent of Australians favored having a U.S. military base in the country, Hanson said. This year, a record-high 59 percent of Australians ranked the alliance with the United States as “very important,” he said.

‘Positive views’ of U.S.

Although China is Australia’s largest trading partner, 44 percent of Australians said they thought China posed a military threat over the next two decades and 77 percent said their country would not be able to defend itself in a conflict, Hanson added.

“That’s extraordinary,” he said. “There’s a pretty strong link why Australians have such positive views of the U.S.”

China is watching the U.S. movement in the region, and the two countries engaged in some diplomatic jousting over economic policy at the weekend Asia Pacific Economic Cooperation summit in Hawaii.

But Gillard attempted to preemptively soothe Chinese concerns over Obama’s visit this week.

“It’s not going to surprise anybody in China that Australia is an ally of the United States,” she said during a news conference in Hawaii this weekend. “They’ve had 60 years of experience seeing what that means for Australia and what it means for the United States.”