After Washington earlier this year accused Pyongyang of supplying Moscow with weapons for its war in Ukraine, photographs in state media showed Kim walking Moscow's Sergei Shoigu through a vast defence exhibition showcasing the North's nuclear missiles and what Seoul-based specialist site NK News said were new unmanned aerial vehicles (UAVs).

Shoigu and a high-ranking Chinese delegation are in Pyongyang as Kim's first-known foreign guests since the start of the Covid-19 pandemic, as the country marks the 70th anniversary of the Korean War armistice, which ended open hostilities and is celebrated as Victory Day.

Kim and Shoigu visited the "Weapons and Equipment Exhibition 2023", the official Korean Central News Agency said, showing photos that featured North Korea's largest intercontinental ballistic missiles, the Hwasong-17, and the Hwasong-18 solid-fuel ICBM.

Russia, a historic ally of North Korea, is one of a handful of nations with which Pyongyang maintains friendly relations.

Kim and Shoigu had earlier discussed "matters of mutual concern in the field of national defence and security and on the regional and international security environment," KCNA said.

The North Korean leader has been steadfast in his support for Moscow's invasion of Ukraine, including, Washington says, supplying rockets and missiles -- a charge Pyongyang has denied.

During the visit, Kim told Shoigu "about the weapons and equipment which were invented and produced" under North Korea's national defence plan and "repeatedly expressed belief that the Russian army and people would achieve big successes", KCNA added.

Shoigu's visit is noteworthy given that Russian defence ministers have not regularly visited Pyongyang since before the collapse of the USSR, experts told AFP.

"Russia may need the potential of North Korean military industry in the realm of conventional weapons, while North Korea may be interested in missile technology transfers from Russia," Vladimir Tikhonov, professor of Korean studies at the University of Oslo, told AFP.

Despite the high-profile coverage of Shoigu's visit, North Korea is likely to be "very careful" about providing Moscow with weapons for its war in Ukraine, Park Won-gon, professor at Ewha University, told AFP.

"If it is confirmed publicly, European countries would also turn adversarial," Park said, adding that North Korea would prefer not to face additional sanctions.

"So it will be careful, but it's possible that Russia will seek more help in secret."

- First foreigners -

Satellite imagery indicates North Korea has been preparing for a large-scale military parade for Thursday's anniversary.

The inclusion of foreign guests at this year's celebrations is a post-pandemic first and hints at new flexibility towards enforcing border controls.

Seoul's military said US and South Korean "intelligence authorities are closely monitoring," Pyongyang's parade prep, adding they were also tracking the country's "weapons development trends".

"We are currently analysing the weapons systems unveiled by North Korea, and for now we have nothing more to say," a spokesperson for the Joint Chiefs of Staff said.

North Korea has imposed a rigid Covid-19 blockade since early 2020, preventing even its own nationals from entering the country.

Beijing is North Korea's most important ally and economic benefactor, their relationship forged in the bloodshed of the Korean War in the 1950s.

Kim Jong Un also met a Chinese delegation led by politburo member Li Hongzhong and told him "the Korean people will never forget the fact that the brave soldiers of the Chinese People's Volunteers shed blood to bring about the war victory," KCNA said.

"The meetings show that Kim is more interested in political theatre than he is concerned about Covid," Leif-Eric Easley, a professor at Ewha University, told AFP.

Park, also at Ewha University, said it was unlikely the visits would lead to a reopening of the North's borders, noting the country's "broken" medical system and that its people had not been vaccinated.

North Korea only resumed some trade with China last year and allowed new Beijing envoy Wang Yajun to take up his position this year. He is the first known senior diplomat to cross into North Korea since the border closure in January 2020.