North Korean leader Kim Jong-un left Russia on his armored train Sunday to return home following a six-day visit to the country, Russian media said.

The train carrying Kim departed the railway station in Russia's Far Eastern city of Artyom as Russian officials saw him off, RIA Novosti news agency said. Kim also waved and gave a salute to the Russian officials.

The North Korean leader visited Russia at the invitation of President Vladimir Putin. On Wednesday, the two held a summit at the Vostochny space center amid growing concern about possible military cooperation between the two countries.

Kim pledged to throw his full support behind Putin, saying the Russian army and people will triumph over "evil" forces, in an apparent endorsement of Russia's war in Ukraine.

Putin told a local news channel following the summit talks at the space center in Russia's Amur region that he sees prospects for military and technical cooperation with the North.

He also said Kim showed "great interest" in rocket technology, pledging to help the recalcitrant regime build its own satellite.

North Korea made attempts in May and August to place a military spy satellite into orbit, but they ended in failure. The country has pledged to launch a third spy satellite in October.

Speculation arose that military cooperation would have been discussed, as Russia apparently needs North Korea's supplies of artillery shells and ammunition for its war in Ukraine, while the North wants high-tech weapons technology from Russia.

This was the longest overseas trip by Kim since taking power. Including travel time, the North Korean leader spent a total of eight days on his visit to Russia.

After departing from Pyongyang by armored train last Sunday, Kim arrived at the rocket launch facility on Wednesday, traveling more than 1,000 kilometers north of the eastern Russian city of Vladivostok, where the two leaders previously met in 2019.

Photos carried by the North's state media showed that Kim was accompanied by the North's top party and military officials, including military marshals Ri Pyong-chol and Pak Jong-chon, and Pak Thae-song, an official in charge of space technology.

The makeup of his entourage and the selection of Russia's space facility as the venue for talks spawned speculation that North Korea may agree to supply Russia with ammunition and weaponry in exchange for food aid and a transfer of weapons technology from Moscow, such as those involving spy satellites and nuclear-powered submarines.

Following the summit, Kim went on a tour of Russia's Far East and visited key military facilities in the region.

On Friday, he visited a Russian aircraft plant that produces advanced fighter jets, including the Sukhoi Su-35, in Komsomolsk-on-Amur.

During his trip to the Yuri Gagarin Aviation Plant, Kim said he was "deeply impressed" with the advanced state of Russian aerospace and aviation technology, according to Pyongyang's state media.

"Saying that he was deeply impressed by the rich independent potential and modernity of the Russian aircraft manufacturing industry and its ceaseless enterprising efforts toward new goals, he sincerely hoped that the plant would make sustained development by achieving higher production growth in the future," the official Korean Central News Agency (KCNA) said.

The next day, Kim held talks with Russian Defense Minister Sergei Shoigu in Vladivostok and talked about strengthening bilateral military cooperation and exchanges.

They "exchanged their constructive opinions on the practical issues arising in further strengthening the strategic and tactical coordination, cooperation and mutual exchange between the armed forces of the two countries and in the fields of their national defence and security," the KCNA said.

The same day Kim also visited the Knevichi Airbase, where he inspected strategic bombers, multi-role fighter jets and other warplanes, as well as Russia's Pacific Sea Fleet to board the Marshal Shaposhnikov frigate, it said.

Source: Yonhap News Agency