WASHINGTON • Three US aircraft carrier strike groups will hold an exercise together in the Western Pacific in the coming days in a rare show of force, as President Donald Trump visits Asia with warnings about the nuclear threat from North Korea, US officials say.

The drill will involve the USS Nimitz, the Ronald Reagan, the Theodore Roosevelt and their accompanying warships, the first time three US aircraft carrier strike groups have exercised together in the region in a decade.

A Japanese destroyer, the Inazuma, will join the armada, two Japanese government officials said, following a separate three-day exercise with the Reagan and two Indian warships in the Sea of Japan that ended on Monday.

The four United States officials and two Japanese sources, speaking on condition of anonymity, did not disclose the date or location of the exercise. Mr Trump has reiterated his tough rhetoric against North Korea over its nuclear and missile programmes since starting a 12-day trip to Asia on Sunday.

The last time three US carrier strike groups exercised together was in 2007, near Guam.

Such large-scale drills serve as a potent reminder of the US ability to rapidly mobilise military force.

In Beijing, Foreign Ministry spokesman Hua Chunying called for restraint during a regular news briefing yesterday when asked about the carriers.

"All relevant sides should exercise restraint, avoid irritating each other, dedicate themselves to lowering the tense situation on the peninsula, and at the same time make positive efforts to get the North Korean nuclear issue back on a track to a resolution via talks," Ms Hua said, reiterating China's long-held position.

REUTERS