Obama to deploy up to 250 Marines to Australia next year under new pact

Move sends a signal the United States is stepping up its commitment to the Asia Pacific region.

President Obama unveiled a pact with Australia on Wednesday to build a military presence there as part of the administration's pivot to the Asia-Pacific region.

Australian Prime Minister Julia Gillard said America will deploy company-sized rotations of 200 to 250 Marines for about six months at a time starting in mid-2012, with the American presence there expected to expand to 2,500 personnel over time. The pact, Gillard said, will allow U.S. military aircraft greater access to Australian Air Force facilities.

"We are two Pacific nations, and with my visit to the region I am making it clear that the United States is stepping up its commitment to the entire Asia Pacific," Obama said alongside Gillard in a joint press conference. The new rotations, Obama said, will "enhance our ability to train, exercise, and operate with allies and partners across the region, and that, in turn, will allow us to work with these nations to respond even faster to a wide range of challenges, including humanitarian crises and disaster relief, as well as promoting security cooperation across the region."

While neither leader said China's expanding naval presence in the Pacific region was the impetus for the pact, Defense Secretary Leon Panetta said in September that the forthcoming agreement would "send a clear signal to the Asia Pacific region that the United States and Australia are going to continue to work together to make very clear to those that would threaten us that we're going to stick together."

Obama himself didn't directly answer a reporter's question about how much the U.S. troop buildup has to do with China's rising influence, but said the U.S. welcomes "a rising, peaceful China" added that "it's important for them to play by the rules of the road."

"There are going to be times where they're not," he said. "And we will send a clear message to them that we think that they need to be on track in terms of accepting the rules and responsibilities that come with being a world power."