Russian Foreign Minister Sergey Lavrov flew to North Korea’s eastern Wonsan city on Friday for a meeting with his North Korean counterpart Choe Son Hui. Relations between Russia and North Korea have been flourishing in recent years, with North Korea supplying troops and ammunitions to support Russia’s war against Ukraine in return for military and economic assistance. That has raised concerns among South Korea, the U.S. and others that Russia might also transfer to North Korea sensitive technologies that can increase the danger of its nuclear and missile programs. After a meeting with Choe on Saturday, Lavrov accused the U.S.,...