Kim Jong Un arrives in Russia for talks with Putin

STORY: In typical fashion North Korean state media confirmed Tuesday (September 12) that leader Kim Jong Un had in fact set off on a rare trip out of the country to visit Russia's Far East.

His private train was headed to an unconfirmed destination - for what the Kremlin described as comprehensive discussions with Vladimir Putin - amid warnings from Washington they should not trade weapons.

The Russian president gave little away to reporters who asked him why he was going to the Vostochny cosmodrome on Tuesday, saying he "had his own agenda there."

U.S. officials have said arms talks between Russia and North Korea are actively advancing - and that Kim and Putin were likely to discuss the war in Ukraine.

Weapons are one thing Pyongyang has at its disposal ... but it and Moscow both deny North Korea could supply arms to Russia, which has expended vast stocks in more than 18 months of war.

Kim could offer artillery rounds from North Korea's large stockpile, but questions about the ammunition's quality may limit the overall impact, military analysts said.

Washington and its allies have expressed concern at recent signs of closer military cooperation between Russia and nuclear-armed North Korea.

Kim's last trip out of the country was also to meet Putin in 2019.

North Korea is one of the few countries to have openly supported Moscow over the Ukraine conflict, and Putin pledged just days ago to "expand bilateral ties in all respects in a planned way by pooling efforts."