On Friday an American warship approached the Paracel Islands, an island chain claimed by Beijing in the South China Sea, to affirm international "freedom of navigation" in the region.

The USS Wayne E. Meyer, a guided-missile destroyer, passed near the islands to contest Beijing's sweeping claims to the seas around the archipelago, which is also claimed by Taiwan and Vietnam.

The Chinese claim would block "innocent passage" by other countries' ships and is "not permitted by international law," a US Seventh Fleet spokeswoman, Commander Reann Mommsen, said.

Friday's was the sixth "freedom of navigation operation" -- or FONOPS in naval jargon -- this year, a clear acceleration in pace.

There were a total of eight in 2017 and 2018, and only six during the entire Obama presidency.

On Wednesday, the US Marine Corps announced it had conducted exercises on the Japanese islet of Tori Shima, hundreds of miles south of Tokyo, to practice landings on "hostile" shores and the seizure of landing strips.

The exercises were clearly designed to highlight the ability of the American military to invade a disputed island and establish a supply base for aerial operations.

"This type of raid gives the commanders in the Indo-Pacific region the ability to project power and conduct expeditionary operations in a potentially contested littoral environment," one of the officers in charge, Commander Anthony Cesaro, said in a statement.

Such a forthright description, coming from a Pentagon hardly known for unguarded talk, reflects the fresh impetus Defense Secretary Mark Esper has given to the US policy of "strategic rivalry" with China and Russia.

Esper, who chose Asia for his first overseas trip only weeks after being sworn in as Pentagon chief, has made clear that the US wants to rapidly deploy new missiles in Asia -- possibly within months -- to counter China's rising military power.

- To 'change the geometry' -

On Thursday, acting US army secretary Ryan McCarthy, speaking in a Senate confirmation hearing, defended the development of such new missiles.

He said the new medium-range conventional missiles Washington wants to develop -- now that the US is no longer constrained by the Intermediate Nuclear Forces (INF) treaty, which the Trump administration abandoned last year -- would "change the geometry within Southeast Asia."

"If we can get the appropriate partnerships, expeditionary basing rights with partners within the region," McCarthy said, "we can change the geometry and basically reverse anti-access, area-denial capabilities that have been invested by near-peer competitors" -- jargon for pushing back against sovereignty claims by China and Russia.

Last month the Pentagon chose the Pacific Ocean for its first test of a conventional medium-range missile since the end of the Cold War -- effectively driving a nail into the coffin of the INF treaty, which banned the use of land-based missiles with ranges of 500 to 5,500 kilometers (310 to 3,400 miles).

And in late August, Washington formally established its Space Command, or Spacecom, a new unified command charged with ensuring US domination in space, where China has been increasingly active.

Beijing rattled US military officials in 2007 when it launched a missile that located and then destroyed a Chinese satellite, in a dramatic demonstration of China's growing ability to militarize space.