The first 250 U.S. Marines will arrive next month in northern Australia where a permanent joint training hub will be based, but a proposal to build a U.S. air base on a remote Australian island in the Indian Ocean is not yet a priority, Defense Minister Stephen Smith said Wednesday.

In November, the United States and Australia announced plans to send more U.S. military aircraft and to rotate up to 2,500 Marines through the northern city of Darwin to better protect American interests across Asia.

The Washington Post newspaper reported Tuesday that U.S. and Australian officials were considering establishing an air base on the Cocos Islands, a pair of coral atolls much closer to Indonesia than to the Australian mainland.

The newspaper reported that aircraft based on the sparsely populated islands would be well positioned to launch spy flights over the South China Sea, where the Chinese navy is becoming increasingly assertive.

Smith said while the Cocos Islands might be included in plans for closer U.S.-Australian military relations, an air base there was not a priority in current discussions.

"Suggestions that we've had detailed discussions at my level about the utilization of Cocos Islands are not correct," Smith told reporters. "We view Cocos as being potentially a long-term strategic location, but that is down the track."

Smith would not give a timeline on when officials will talk about Cocos in-depth but said, "I'm not expecting any detailed discussions in the near future."

Smith said the allies were giving priority to establishing the Marine training base in Darwin, increasing U.S. access to mainland Australian military airfields and allowing greater naval access to the Australia's Indian Ocean navy base HMAS Stirling, south of the west coast city of Perth.

Smith said the first 250 Marines would arrive in Darwin in early April as part of the new plan, which analysts agree is a response to the rise of China.