Chinese President Xi Jinping called for all sides to exercise restraint on Monday in a telephone call about North Korea with U.S. President Donald Trump, as Japan conducted exercises with a U.S. aircraft carrier strike group headed for Korean waters.

Trump sent the carrier group for exercises in waters off the Korean peninsula as a warning, amid growing fears North Korea could conduct another nuclear test in defiance of United Nations sanctions.

Angered by the approach of the USS Carl Vinson carrier group, a defiant North Korea said on Monday the deployment was "an extremely dangerous act by those who plan a nuclear war to invade."

"The United States should not run amok and should consider carefully any catastrophic consequence from its foolish military provocative act," Rodong Sinmun, the official newspaper of the North's ruling Workers' Party, said in a commentary on Monday.

"What's only laid for aggressors is dead bodies," the newspaper said.

Two Japanese destroyers have joined the carrier group for exercises in the western Pacific, and South Korea said on Monday it was also in talks about holding joint naval exercises.

The United States and its allies fear North Korea could be preparing to conduct another nuclear test or launch more ballistic missiles.

China is North Korea's sole major ally but has been angered by its nuclear and missile programs and is frustrated by Pyongyang's belligerence.

China, which has repeatedly called for the de-nuclearization of the Korean peninsula, is increasingly worried the situation could spin out of control, leading to war and a chaotic collapse of its isolated, impoverished neighbor.

Xi told Trump in their latest telephone conversation that China resolutely opposed any actions that ran counter to U.N. Security Council resolutions, the Chinese foreign ministry said.

China "hopes that all relevant sides exercise restraint, and avoid doing anything to worsen the tense situation on the peninsula", the ministry said in a statement, paraphrasing Xi.

The nuclear issue could only be resolved quickly with all relevant countries pulling in the same direction, and China was willing to work with all parties, including the United States, to ensure peace, Xi said.

The issue has gained added urgency as North Korea prepares to celebrate the 85th anniversary of the foundation of its Korean People's Army on Tuesday. It has marked similar events in the past with nuclear tests or missile launches.

Trump was critical of China in his election campaign but he has in recent days praised its efforts to rein in what he called the "menace of North Korea."

A Chinese foreign ministry spokesman said the call between the two presidents was the latest manifestation of their close communication, which was good for both of their countries and the world.