The United States, South Korea and Japan pledged Wednesday to cooperate on North Korea as their top diplomats met in London, coming together despite renewed tensions between the Asian nations.

Joined by aides, US Secretary of State Antony Blinken sat in the centre of a U-shaped table with his Japanese and South Korean counterparts Toshimitsu Motegi and Chung Eui-yong on each side in a hotel conference room on the sidelines of a Group of Seven meeting.

The State Department said the meeting was meant to "promote trilateral solidarity" and discuss a policy review by President Joe Biden that looks to resume diplomacy with North Korea.

Blinken and the two ministers "reaffirmed their commitment to concerted trilateral cooperation toward denuclearisation of the Korean peninsula, as well as other issues of mutual interest," State Department spokesman Ned Price said.

The South Korean foreign ministry similarly said the three "reaffirmed the importance of the Korea-US-Japan trilateral cooperation" and committed to work "to promote peace, security and prosperity in the region".

The two Asian nations are both treaty-bound allies of the United States but have long had friction due to the legacy of Japan's harsh colonial rule over the Korean peninsula.

South Korea last month voiced "deep disappointment" after Japanese Prime Minister Yoshihide Suga sent an offering to the Yasukuni shrine, which venerates war dead including convicted war criminals, although leaders in Tokyo have in recent years refrained from the more explosive step of visiting.

Relations deteriorated sharply in 2019, with South Korea pulling back at the last minute from terminating an agreement on sharing intelligence with Japan on North Korea.

Since taking office, Biden has put an emphasis on working with allies. Blinken and Defence Secretary Lloyd Austin visited Tokyo and Seoul together on their first foreign trip, and the Japanese and South Korean national security advisers met jointly near Washington as the administration concluded its North Korea policy review.

Earlier this week, the top US military officer, General Mark Milley, met jointly with his Japanese and South Korean counterparts in Hawaii.

The Biden administration in its policy review called for seeking practical progress with North Korea, avoiding the flashy, high-stakes summitry of former president Donald Trump.