Upon arriving in Vladivostok, a Pacific port city near the Chinese and North Korean borders, Kim was greeted by Defence Minister Sergei Shoigu and an honour guard.

Shoigu and Kim were seen smiling as they inspected some of Russia's most advanced nuclear bombers at an airfield before boarding a warship, a video released by the Russian defence ministry showed.

Kim's extended tour of Russia's far eastern region, which began on Tuesday, has focused extensively on military matters, as evidenced by his own officer-dominated entourage, a symbolic exchange of rifles with President Vladimir Putin and a tour of a fighter jet factory in Komsomolsk-on-Amur.

Historic allies, Russia and the North are both under rafts of global sanctions -- Moscow for its Ukraine assault, Pyongyang for its nuclear tests.

Kim's first official visit abroad since the coronavirus pandemic has fanned Western fears that Moscow and Pyongyang will defy sanctions and strike an arms deal.

Moscow is believed to be interested in buying North Korean ammunition to continue fighting in Ukraine, while Pyongyang wants Russia's help to develop its internationally condemned missile programme.

The Kremlin has said no agreement has or will be signed.

After meeting Kim on Wednesday at the Vostochny cosmodrome, roughly 8,000 kilometres (5,000 miles) from Moscow, Putin talked up the prospect of greater cooperation with North Korea and the "possibilities" for military ties.

At the Knevichi airfield in Vladivostok on Saturday, Kim was shown strategic Tu-160, Tu-95MS and Tu-22M3 bombers.

"These aircraft form the air component of Russia's strategic nuclear forces," the defence ministry said in a statement.

According to footage released by Moscow, Kim was shown carefully listening to senior representatives of the Russian military and inspecting the aircraft.

Russian officials also showed the reclusive leader a range of fighter jets as well as a hypersonic, air-launched Kinzhal missile system.

Kim and Shoigu then boarded the Marshal Shaposhnikov, an anti-submarine destroyer, where the head of the Russian navy, Admiral Nikolai Yevmenov, explained the characteristics of the warship and the weapons it carries.

Kim was also expected to visit the Far Eastern Federal University as well as marine biology laboratories at the Russian Academy of Sciences in Vladivostok.

Colleges in Russia's Far East have historically accepted North Korean students.

- 'Troubling' cooperation -

Kim is visiting Russia as Putin seeks to bolster alliances with other world leaders ostracised by Western countries.

Kim and Putin's gifting each other rifles at the spaceport summit on Wednesday further fuelled speculation that an arms export deal could be on the table, despite Western warnings.

Kremlin spokesman Dmitry Peskov told reporters on Friday that no agreements had been signed during Kim's trip, and "there was no plan to sign any".

While meeting Kim, Putin accepted an invitation to visit North Korea, according to the Kremlin, and offered to send a North Korean to space, which would be a first.

Moscow also mentioned the possibility of helping North Korea manufacture satellites, a prospect that has alarmed Washington.

The cooperation announced during Kim's Russia trip is "quite troubling and would potentially be in violation of multiple UN Security Council resolutions", US State Department spokesman Matthew Miller told reports after the leaders' summit.

North Korean satellites, he noted, have been used to develop Pyongyang's ballistic missiles.

Pyongyang recently failed twice in its bid to put a military spy satellite into orbit.