The buildup of U.S. Marines permanently stationed in Australia will start next year with the arrival of 250 soldiers rising to 2,500 by 2017, U.S. President Barack Obama and Prime Minister Julia Gillard jointly announced Wednesday night.

The U.S. Marine Air-Ground Task Force will spend six months training with Australian forces in the Northern Territory until they are replaced by another batch of Marines, who will continue the joint practice, according to Obama after arriving in Canberra for the first time. The training will be conducted in the Australian military bases of Bradshaw, Tindal, and Mount Bundey.

Obama also said that the number of U.S. warplanes visiting Australia will be increased in the next two years. Aside from U.S. B-52 bombers, Australia will see American fighters, refuellers, spy planes and transporters landing and taking off at the Tindal Air Force Base.

U.S. ships and submarines will also regularly call at the Stirling naval base, south of Perth, he added.

"We are here to stay, this is a region of huge strategic importance to us. We are increasing our co-operation and, I'd add, America's commitment to this region. This deepening of our alliance sends a clear message of our commitment to this region, a commitment that is enduring and unwavering," Obama declared, according to Adelaide Now.

Gillard said the increased U.S. military presence in Australia aims to strengthen the two countries' defence alliance and cooperation in the Asia-Pacific region.

"It will mean that we are postured to better respond together, along with other partners in the Asia-Pacific, to any regional contingency including the provision of humanitarian assistance and dealing with natural disasters," Adelaide Now quoted her as saying.

Meanwhile, China, which was informed beforehand about the announcement through diplomatic channel, reacted with Liu Weimin, a spokesman of China's Ministry of Foreign Affairs, saying, "It may not be appropriate to intensify and expand military alliances at a time when the economy is still recovering. The move may not be in the interest of countries in the region," according to the Chinese daily The Global Times.

"The US has repeatedly said it has no intention to constrain China, and has expressed its support of a strong, prosperous and stable China. We hope the US will fulfill its pledges," Liu said.

The expansion of the Australia-U.S. military cooperation is seen as a posturing by Washington in the Asia Pacific to counter China's growing influence in the region.