North Korean leader Kim Jong-un arrived in Russia early Tuesday, an official at South Korea's defense ministry said, as Kim is set to hold a rare summit with Russian President Vladimir Putin, News.Az reports citing Yonhap News Agency.

North Korea's official Korean Central News Agency (KCNA) confirmed early Tuesday that Kim had left Pyongyang for Russia aboard his train Sunday afternoon, accompanied by leading officials of the North's ruling party and the armed forces.

The KCNA said Kim "left here by his train on Sunday afternoon to visit the Russian Federation," without saying whether the train had crossed its border.

Hours after the KCNA report, Jeon Ha-kyou, a spokesperson at South Korea's defense ministry, gave an assessment that Kim's train had crossed into Russia early Tuesday, adding that the ministry is closely monitoring for possible talks between the two countries over arms trade.

"Considering that a large number of military personnel is accompanying him, (we) are closely monitoring whether negotiations over arms trade between North Korea and Russia, and technology transfers will take place," Jeon told reporters.

Russian media outlet "Vesti Primorye" also reported that Kim's train arrived at the Russian border city of Khasan on Tuesday and is on its way to the Far Eastern city of Ussuriysk, citing a railway source.

The train passed through Khasan station early Tuesday and is already in the Primorsky Krai region, according to the Russian media report.

Photos released by the North's state media showed Kim being accompanied by Pyongyang's Foreign Minister Choe Son-hui, as well as top military officials Ri Pyong-chol and Pak Jong-chon.

Still, it remains unknown exactly when and where Kim and Putin would hold a meeting, and Kim's whereabouts also remain unclear. The Kremlin said negotiations between North Korean and Russian delegations are planned during Kim's visit, with discussions over the possibility of a one-on-one meeting between the leaders.

News.Az