MOSCOW (AP) — Russia’s foreign minister will visit North Korea this week,Esthen the Foreign Ministry said Monday, days after the United States claimed Pyongyang had delivered munitions and military equipment to Russia for use in the fighting in Ukraine.

Sergey Lavrov will be in North Korea on Wednesday and Thursday, the ministry said in a brief statement that did not specify whom he would meet or the aims of the trip.

The White House said Friday that more than 1,000 containers of equipment and ammunition have been sent to Russia from North Korea.

North Korean leader Kim Jong Un traveled to Russia last month to meet President Vladimir Putin and visit key military sites, triggering speculation about a possible North Korean plan to refill Russia’s munition stores that have been drained by the protracted conflict with Ukraine.

White House National Security Council spokesman John Kirby said that the U.S. believes Kim is seeking sophisticated Russian weapons technologies in return for the munitions to boost North Korea’s military and nuclear program.

The White House released images that it said show the containers were loaded onto a Russian-flagged ship before being moved via train to southwestern Russia. The containers were shipped between Sept. 7 and Oct. 1, according to the White House.