Australia will invest $582 million to improve bases and training areas in its Northern Territory that are used by a rotational force of U.S. Marines, the country’s Defence Department announced Wednesday.

The country’s defense minister, Peter Dutton, said the upgrades will ensure that the Australian Defence Force delivers world-class training and engagement with allies and other nations through joint exercises, including with the Marines.

The announcement comes amid deteriorating relations between Australia and its largest trading partner, China.

“These new initiatives should help to make northern Australia an even more attractive location for many types of training and exercising by United States forces,” according to Ross Babbage, a former Australian assistant defense secretary.

Australia will spend A$747 million ($580 million) to upgrade four military bases in its north and expand war games with the United States, Prime Minister Scott Morrison will say on Wednesday.

An airstrip in the Northern Territory will be lengthened to support larger aircraft, firing ranges overhauled and new training facilities set up for defence personnel and U.S. marines, according to extracts of the announcement seen by Reuters.

“Working with the United States, our allies and Indo-Pacific neighbours, we will continue to advance Australia’s interests by investing in the Australian Defence Force,” Prime Minister Scott Morrison will say.

Australian Defence Minister Peter Dutton on Sunday said a conflict between China and Taiwan “should not be discounted”.

THE build up of the US Marine Air-Ground Task Force in Darwin moved into overdrive this week with a squadron of MV-22B Ospreys, a detachment of UH-1Y Venoms and AH-1Z Vipers from Marine Light Attack Helicopter Squadron 367 joining a new tranche of 300 US Marines who touched down in the Top End.

Other heavy fighting equipment involved in the rotation includes an artillery battery from 3rd Battalion, 11th Marine Regiment; a detachment from 1st Combat Engineer Battalion; a detachment of RQ-20B Pumas and RQ-21A Blackjacks from Marine Unmanned Aerial Vehicle Squadron 3; and a collection of transportation and engineering assets from Combat Logistics Battalion 7.

More than 1300 US military personnel are now in Darwin as part of the 10th Marine Rotational Force – Darwin (C). This will grow to 2200.

The 22-year-old marine who arrived in the Northern Territory earlier this week is part of the annual training rotation that will see thousands of marines fly into Darwin this year.

[unironically] - more to come.

The head of the US Navy's Indo-Pacific Command is urging Congress to build a new missile defence base in the Pacific as part of a larger strategy to counter China's military threat to the region.

The Pentagon is seeking $US77 million ($98 million) to build a permanent "land-based integrated air and missile defence system and associated weapon delivery system on Guam", as outlined in the Indo-Pacific Deterrence Act.

In addition to the defence system, which is designed to track down and destroy missiles before they do harm, the US is considering an increase to its ground-based missiles on Guam that could fire on targets over 500 kilometres away.

Almost a third of Guam's land is controlled by the US military, and Ms McManus fears its presence is destroying the island's natural environment.