(Adds details of military equipment bought by U.S. Marines, paragraph 9)
By Colin Packham
SYDNEY, March 23 (Reuters) - The United States will deploy a record number of Marines to train in Australia, the Australian defence minister said on Friday, as Washington seeks to counter what it describes as Chinese aggression in the region.
Payne said 1,587 U.S. Marines will spend six months training in Australia's remote north, an increase of nearly 27 percent on its 2017 rotation for the programme known as the Force Posture Initiatives.
"The U.S. military plays a vital role in underwriting security and stability across the Indo-Pacific, and the Force Posture Initiatives will be an essential component in preserving stability and security over the coming decades," Defence Minister Marise Payne said in a statement.
The deployment, first introduced in 2011 as part of a U.S. "pivot" to Asia, has emerged as a key indicator of Washington's commitment to the region under U.S. President Donald Trump and his willingness to counter Chinese influence in a region where tensions have spiked amid disputes over the South China Sea.
China claims most of the South China Sea, an important trade route that is also believed to contain large quantities of oil and natural gas, and has been building artificial islands on reefs, some with ports and air strips.
In a move likely to irk Beijing, the U.S. Marines will train with personnel from Australia, Indonesia, Japan, Malaysia, the Philippines, Singapore and Thailand, some of which also have claims in the South China Sea.
"China will monitor whatever the U.S. does and it would prefer that the United States not work with the Asian countries included in these exercises," said Euan Graham, director of the international security programme at Australian think tank the Lowy Institute.
"Beijing would like to deal one-on-one with Southeast Asia nations that have counter claims," he said.
The U.S. Marines will also bring additional military equipment, including helicopters and F-18 jets, Payne said.
The military deployment also threatens to further weaken Australia-Chinese relations.
Australia, a staunch U.S. ally with no claim to the South China Sea, has long maintained its neutrality in the dispute to protect its economic relationship with China.
But bilateral relations have soured in recent months after Australian Prime Minister Malcolm Turnbull said China was improperly interfering in Canberra's affairs, an accusation that triggered a rare protest from Beijing.