A U.S. official said that North Korea recently provided several dozen ballistic missiles as well as launchers to Russia.

Responding to an inquiry by Yonhap News Agency on Thursday regarding a recent Wall Street Journal report that Pyongyang provided ballistic missiles to Moscow, the official said that Russia has become increasingly isolated due to sanctions and export controls.

The limitations have forced Moscow to rely on other countries in similar positions to secure military equipment, the official said, including North Korea.

John Kirby, a White House spokesperson for national security issues, also confirmed the missile shipments during a press briefing on Thursday, saying that Russian forces launched at least one of the North Korean missiles into Ukraine last Saturday and it landed in an open field in the Zaporizhzhia region.

South Korean and U.S. intelligence authorities believe that North Korea transferred a large amount of military supplies, including artillery shells and missiles, to Russia around the time when Russian defense minister Sergei Shoigu visited the North in late July of last year and met with regime leader Kim Jong-un.

The authorities suspect that the shipments continued after a summit between Kim and Russian President Vladimir Putin on September 13 last year, with Russian satellite launch technology going the other way that was used in Pyongyang's military reconnaissance satellite launch last month.

Arms trade with North Korea constitutes a violation of UN Security Council resolutions.