CANBERRA, Australia (AP) — Australia on Thursday rejected a proposal by a Washington-based think tank to base a nuclear aircraft carrier strike group on Australia's west coast as part of a shift of U.S. military might to the Asia-Pacific region.

A Pentagon-commissioned report by the Center for Strategic and International Studies on repositioning U.S. forces in the region suggested relocating an aircraft carrier from the U.S. East Coast to an Australian naval base south of the city of Perth.

But Defense Minister Stephen Smith said Thursday that while negotiations were under way to increase U.S. navy access to Australia's Indian Ocean base, HMAS Stirling, it would never become a U.S. military base.

"We have made it crystal clear from the first moment — we don't have United States military bases in Australia. We don't see the need for that," Smith told Australian Broadcasting Corp. television.

Smith said the think tank's proposal was not endorsed by the U.S. government.

"It's a suggestion by an independent think tank. It's not one we're proposing to take up," he said.

The report said more than $1 billion would need to be spent to make HMAS Stirling capable of becoming a home port to a nuclear carrier that would become the flagship of a carrier strike group.

Such a group would typically include two guided missile cruisers, two or three guided missile destroyers, two nuclear-powered submarines, a supply ship and up to nine squadrons of aircraft.

The Australian base would give the United States a second carrier strike group in the Asia-Pacific, the first with an existing Japanese home port in Yokosuka.

Washington has been forging closer military ties with countries in the region and has announced that 60 percent of the U.S. Navy's fleet will be based in the Asia-Pacific by 2020, up from less than 55 percent now.

Australia is a staunch U.S. ally and the only country to fight alongside the Unites States in every major conflict since the start of the 20th century.

Washington and Canberra announced late last year an agreement on closer military cooperation in which up to 2,500 U.S. Marines would rotate through a joint military training hub in the northern Australian city of Darwin. The U.S. Air Force will also make greater use of airfields and bombing ranges in the Australian Outback.

China — Australia's most important trade partner — has blasted the closer bilateral military ties as a return the Cold War divisions that risked the peace and security of the region.

Hugh White, head of Australian National University's Strategic and Defense Studies Center, noted that American combat troops had not been based in Australia since World War II and said that was unlikely to change in the future.

He said Chinese objections were the major reason why Australia was unlikely to ever allow U.S. bases on its soil.

"The government was surprised that China reacted as negatively as it has to the decision to have Marines rotate deployments through Darwin, and I think they'll be very careful not to risk further displeasure from China by doing anything that suggests they're supporting a U.S. military buildup in Asia," White said.

"There's a concern that the more the U.S. builds up its military posture in the Western Pacific as part of President Barack Obama's pivot to Asia, the higher the risk that the U.S.-China relationship will become more competitive, more adversarial, more hostile, and that pushes Australia close to the point of having to make a choice between the U.S. and China, and that's something we badly want to avoid," he said.

The U.S. in recent decades has had three exclusive military intelligence communication bases in Australia. But they were targeted by protesters, and with pressure from Australian governments became joint U.S.-Australian facilities.

The only one remaining is the top secret Joint Defense Space Research Facility at Pine Gap in central Australia.