PYONGYANG, July 25 (AFP) - North Korea will this week welcome Russia's defence minister and a high-level Chinese delegation to Pyongyang for Korean War armistice anniversary celebrations, state media said Tuesday, a sign it could be reopening its borders to high-level visitors after a lengthy pandemic closure.

"A military delegation of the Russian Federation led by Defence Minister Sergei Shoigu will pay a congratulatory visit to the DPRK," the Korean Central News Agency said, a day after it confirmed a Chinese delegation would also attend the Thursday event.

Russia, one of Pyongyang's historic allies, remains one of a handful of nations that maintains friendly relations with the North, and its leader Kim Jong Un has recently been steadfast in his support for Moscow's invasion of Ukraine, including, Washington says, supplying rockets and missiles.

"This visit will contribute to strengthening Russian-North Korean military ties and will be an important step in the development of cooperation between the two countries," the Russian Defence Ministry said in a statement.

China, North Korea's main trading partner, also confirmed Tuesday it would send a delegation led by Politburo member Li Hongzhong.

The foreign visitors are set to attend events in Pyongyang to mark 70 years since the signing of the armistice, known as Victory Day in the North, which KCNA said would be celebrated in a "grand manner that will go down in history".

A large-scale military parade and other events are expected to be held this week, with satellite images indicating that soldiers and civilians have been training for the parade for months, Seoul-based specialist site NK News reported.

Leader Kim's biggest nuclear-capable missiles and other military capabilities are likely to roll through Kim Il Sung Square during the event, it added.