WASHINGTON -- North Korean leader Kim Jong Un plans to travel to Russia this month to meet Russian President Vladimir Putin to discuss the possibility of supplying weapons for the war in Ukraine, the New York Times reported on Monday, citing U.S. and allied sources.

Kim would travel from Pyongyang, probably by armored train, to Vladivostok, on the Pacific Coast of Russia, where he would meet with Putin, the newspaper said.

The White House did not immediately respond to a request for comment.

The planned trip would come as Russia discusses holding joint military exercises with North Korea and after Russian Defense Minister Sergei Shoigu had tried on a visit to North Korea to convince Pyongyang to sell artillery ammunition to Russia.

The U.S. has previously warned that North Korea could provide more weapons to Russia, whose forces invaded Ukraine in February 2022, a war that the United States and its European allies vehemently oppose and that Moscow calls a "special military operation."

White House national security spokesman John Kirby said on Aug. 30 that the United States was concerned that arms negotiations between the two countries were advancing actively.

(Reporting by Jasper Ward and Kanishka Singh; Editing by Scott Malone and Sandra Maler)