US national security adviser said the US Coast Guard (USCG) was basing Enhanced Response Cutters in the western Pacific for maritime security missions, citing illegal fishing and harassment of vessels by China.
In a statement, Mr Robert O'Brien also said the Coast Guard planned to evaluate next fiscal year the feasibility of basing Fast Response Cutters in American Samoa in the South Pacific.
The statement described the United States as a Pacific power and added that China's illegal, unreported, and unregulated fishing, and harassment of vessels operating in the exclusive economic zones of other countries in the Indo-Pacific threatens our sovereignty, as well as the sovereignty of our Pacific neighbors and endangers regional stability.
It said US efforts, including by the Coast Guard, were critical to countering these destabilizing and malign actions.
To that end, the USCG is strategically home porting significantly enhanced Fast Response Cutters ... in the western Pacific, the statement said, without detailing where the vessels would be based or how many were involved.
Mr O'Brien said the new-generation Coast Guard vessels would conduct maritime security missions, such as fisheries patrols, and enhance maritime-domain awareness and enforcement efforts in collaboration with regional partners who have limited offshore surveillance and enforcement capacity.
Enhancing the presence of the USCG in the Indo-Pacific ensures the United States will remain the maritime partner of choice in the region, his statement said.
Mr Pompeo led a meeting of foreign ministers from India, Japan and Australia this month in Tokyo, a grouping Washington hopes to develop as a bulwark against China's growing assertiveness and extensive maritime claims in the region, including to most of the strategic South China Sea.
The US Navy regularly angers China by conducting what it calls freedom of navigation operations close to some of the islands China occupies that are also claimed by other states.
O'Brien's announcement comes less than two weeks ahead of the Nov 3 US presidential election, in which President Donald Trump's campaign has made a tough approach to China a major foreign policy theme.