The scheduled deployment of U.S. Marines in Australia will commence next month, reports said, with the initial 10 percent of the announced number of troops set to be shipped to Darwin.

The report was confirmed Tuesday by First Brigade commander Brig Gen Gus McLachlan, who told ABC that "we have got about 250 arriving in early April."

"This first year is almost just a foot in the door, proof of concept, and obviously it will build up in a pretty measured pace in the next few years," McLachlan added.

As many as 2500 U.S. service members will be stationed in the northern region of Australia as part of the enhanced security arrangements between Canberra and Washington.

The phased deployment will be completed by 2016, Aussie and U.S. officials said.

In a joint press conference that U.S. President Barack Obama had hosted with Prime Minister Julia Gillard, the move was explained by Obama as America's way of refocusing its attention to the Asia-Pacific region.

The region has emerged lately as an important economic area, where most of the developing nations, led by China, were mostly located.

Also, the race for economic dominance has led countries to search for more energy sources, with the Spratlys - a collection of atolls in the South China Sea - emerging as the likely concentration of the next flashpoint in the region.

Beneath the atolls were vast reserves of oil and natural gas, experts said, prompting China and other countries to lay claim on the territory.

The U.S. has acknowledged of the rising significance of its continued presence in the region when Obama declared that "this is a region of huge strategic importance to us ... and we are here to stay."

"We are going to make sure that we are able to fulfil our leadership goal in the Asia-Pacific region," the U.S. president stressed.

And displaying that leadership assertiveness will come in the form of thousands of U.S Marines, along with combat planes and warships, to be stationed in the country's Northern Territory.

NT's proximity with Australia's Asian neighbours were seen by defence experts as the main reason the U.S. had requested military access in the region.

America needs to make its huge presence felt in the face of China's rising influence in the region, experts said, though U.S. officials have previously denied that Washington's security pact with Australia will be used to contain China.

Apart from conducting navy exercises, the closer military ties of Australia and the United States will also focus on disaster response and rescue drills, officials of the nations said.