SEOUL, June 25 (Reuters) - North Korea on Saturday condemned "aggression moves" by Washington and Seoul, vowing to take revenge as it marked the 72nd anniversary of the outbreak of the Korean War at a time of rising tension on the Korean Peninsula.

Amid concerns North Korea could be preparing to conduct its first nuclear test in five years, South Korean President Yoon Suk-yeol and U.S.
President Joe Biden agreed in May to deploy more U.S. weapons if it was necessary to deter the North.

The North's state news agency KCNA said on Saturday a number of workers' organisations had held meetings to "vow revenge on the U.S. imperialists", blaming the United States for starting the 1950-1953 Korean War.

The war ended in an armistice rather than a peace treaty, meaning U.S.-led U.N.

forces are still technically at war with North Korea.

According to the KCNA report, Pyongyang denounced Washington over what it called "aggression moves" carried out with South Korea and Japan, and said the U.S. push to deploy "strategic assets" on the South was aimed at provoking another war.

Strategic assets can typically include aircraft carriers, long-range bomber aircraft or missile submarines.

"Such insolent behaviour of the U.S. fans the anger and revenge of the Korean people," KCNA said.

Marking the war anniversary in Seoul, Yoon pledged to do his utmost to protect freedom and peace.

"We will maintain strong security posture based on South Korea-U.S. alliance and a strong military backed by science and technology," he wrote on Facebook.

Saturday's anniversary came amid concerns Pyongyang could conduct what would be its seventh nuclear test, which U.S.

and South Korean officials have said could take place "any time" now. (Reporting by Soo-hyang Choi Editing by Helen Popper )