North Korean leader Kim Jong Un arrived in Russia aboard his personal armored train early Tuesday, with Kim expected to meet Russian President Vladimir Putin to discuss a potential arms deal amid Moscow's deepening isolation over the war in Ukraine.

Kim was believed to have entered the country aboard his bulletproof luxury train, South Korea's Defense Ministry said, with Russia's RIA Novosti news agency reporting that the train had crossed into the Primorsky region from North Korea.

Earlier Tuesday, the North’s official Korean Central News Agency said Kim had left Pyongyang “by his train on Sunday afternoon to visit the Russian Federation.” Photos released by KCNA showed that Kim traveled with Foreign Minister Choe Son Hui, senior military official Ri Pyong Chol and munitions industry official Jo Chun Ryong, among others, a signal that arms transfers could be on the leaders' agenda.