North Korean leader Kim Jong Un has arrived in Russia
North Korean leader Kim Jong Un has arrived in Russia AFP

President Vladimir Putin and North Korea's Kim Jong Un arrived at the Vostochny Cosmodrome Wednesday, Russian agencies said, set for rare talks that could lead to a weapons deal the United States has warned would violate international sanctions.

Accompanied by an entourage that suggested a strong military focus for the summit, the North Korean leader travelled overland to Russia in his bullet-proof train, the official Korean Central News Agency reported.

While Kim was out of the country, North Korea fired two ballistic missiles on Wednesday, the South Korean military said, the latest in a string of sanctions-busting tests.

Kim said his visit -- a rare foreign trip and his first since the pandemic -- was "a clear manifestation" of North Korea "prioritising the strategic importance" of its ties with Russia.

The pair are meeting at the Vostochny Cosmodrome, a Russian spaceport some 1,000 kilometres (620 miles) from Vladivostok, where, according to Japan's Kyodo News Agency, "security has been stepped up".

Russian Defence Minister Sergei Shoigu -- who visited Pyongyang in July and has recently mooted bilateral joint naval drills -- will take part in the negotiations, Putin's press secretary Dmitry Peskov said, RIA Novosti and TASS reported.

Kim is accompanied by top military officials including Korean People's Army Marshal Pak Jong Chon and Munitions Industry Department Director Jo Chun Ryong.

The meeting at the cosmodrome would be symbolic and send a signal that Russia might help North Korea with its rocketry and satellite programmes, experts said.

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

"The spaceport seems to be the optimal location because it responds to mutual interests, such as providing satellite technology requested by North Korea," An Chan-il, a defector-turned-researcher who runs the World Institute for North Korea Studies, told AFP.

Russia is eager for North Korea's stockpile of artillery shells likely for use in Ukraine, while Pyongyang is looking for help in upgrading its Soviet-era equipment especially for its air force and navy, he said.

"If North Korea's multiple rocket launchers and other artillery shells are provided to Russia in large quantities, it could have a significant impact on the war in Ukraine," he added.

Russia's natural resources minister Alexander Kozlov greeted Kim at the station and gave him historic autographed photographs of Soviet cosmonauts, including Yuri Gagarin, Kozlov's ministry told TASS.

Russia and North Korea's communication is back on a pre-Covid track with dialogue "actively developing", foreign ministry spokeswoman Maria Zakharova told TASS.

"Our contacts are developing literally on a daily basis in a number of areas."

The White House warned last week that North Korea would "pay a price" if it supplies Russia with weaponry for the conflict in Ukraine.

Kim is also risking the displeasure of his other major ally Beijing by meeting Putin, Vladimir Tikhonov, professor of Korean studies at the University of Oslo, told AFP.

"China will be hardly too happy about Russia entering into what Chinese consider their monopoly territory," he said, adding Beijing would be worried about the regional destablisation impact of any transfer of Russian military technology to Pyongyang.

Kim and Putin "may conduct an exchange of North Korea's old-age, Soviet-type ammo for Russia's newer military tech or hard currency (or wheat).

"Tactically, they both gain, by getting what they need right now. In a longer term though, Russia's important ties to Seoul will be dealt irreparable damage."