Russian Foreign Minister Sergei Lavrov arrived in North Korea on Wednesday amid concerns about advanced nuclear weapons and satellite technology transfers between Moscow and Pyongyang after evidence emerged of large-scale cargo shipments from North Korea to Russia on a previously unknown shipping route.

Russia’s TASS news agency reported that Lavrov may brief the North Korean government on the results of Russian President Vladimir Putin’s recent visit to China and discuss leader Kim Jong-un’s invitation to Putin to visit Pyongyang.

On Monday, the London-based security think tank Royal United Services Institute released dozens of high-resolution commercial satellite images that showed two Russian ships with connections to the country’s military transport networks making multiple trips to North Korea.

The White House last week also released satellite images showing the ships collecting cargo from North Korea and delivering it to a Russian military port on multiple occasions over the past two months.

Sung Kim, the U.S. special representative for North Korea, said Tuesday the United States is “deeply concerned about what Russia is providing the DPRK in return” for the cargo shipments, referring to the North by the acronym for its official name, the Democratic People’s Republic of Korea.

“This expansive military cooperation undermines the global nonproliferation regime and threatens stability and security,” he added.

Kim made the remark during a three-way meeting with his South Korean and Japanese counterparts, Kim Gunn and Hiroyuki Namazu, both of whom also condemned the North’s arms trade as threatening regional stability.

During a press briefing on Friday, where the images were first disclosed, U.S. National Security Council spokesperson John Kirby said that Washington has information “that North Korea has delivered arms to Russia for use in Ukraine” and that North Korea “has provided Russia with more than 1,000 containers of military equipment and munitions.”

U.S. intelligence assessments have concluded that Russia is seeking North Korean assistance to obtain weaponry to restock dwindling supplies for its war in Ukraine.

Ever since the 1950-53 Korean War ended only in an armistice, both Koreas have stockpiled large numbers of conventional weapons to maintain their readiness in case hostilities resume.

The North’s high production capacity for artillery shells and rockets compatible with Soviet and Russian weapons systems being used against Ukraine could significantly augment Russia’s efforts to scale up domestic weapons production.

In return for providing war materiel, North Korea likely seeks to secure military support from Russia, including fighter jets, surface-to-air missiles, armored vehicles and cutting-edge technologies for nuclear and missile advancement, according to South Korean and U.S. officials.

Kim toured a Russian fighter jet factory and a Russian spaceport during his trip last month.

While in Russia, Kim called his country’s relations with Moscow his “top priority” and voiced unequivocal support for Putin in his “sacred” war in Ukraine.

Analysts believe that Russian assistance, especially in satellite and nuclear weapons technology, would significantly increase the threat posed by the North’s advancing weapons programs.

The North Korean leader Kim Jong-un previously mentioned a spy satellite as one of several sophisticated military assets sought by his regime.

Other items on Kim’s wish list, detailed at a ruling Workers’ Party meeting in January 2021, included “miniaturized and tactical” nuclear weapons, “super-large hydrogen bombs,” mid-to-long range cruise missiles, antiaircraft rocket systems, heavy tanks, howitzers, multiple-warhead missiles, new types of ballistic missiles, unmanned aerial vehicles and “hypersonic gliding flight warheads.”

The North has since carried out two spy satellite launches, one in May and another in August.

Both ended in failure during the second-stage separation of the satellite launch vehicle.

BY MICHAEL LEE [lee.junhyuk@joongang.co.kr]