Russian President Vladimir V. Putin is scheduled to visit North Korea for a two-day trip starting Tuesday to meet with one of the main arms suppliers to the war against Ukraine.
As the war dragged on, Russia found itself in desperate need of conventional weapons, including artillery shells, which North Korea could supply.
Here's some background on what's happened so far and why it matters.
What do we know about previous arms shipments?
The United States first accused North Korea of ​​selling artillery to Russia in September 2022, seven months after the start of the war, an accusation that North Korea denied at the time.
Then, last August, the White House warned that Putin and North Korean leader Kim Jong Un were holding arms negotiations, and in September Kim visited Putin in eastern Russia. Just weeks later, U.S. officials said North Korea had sent more than 1,000 containers of weapons to Russia for use in the war in Ukraine. By March, North Korea had sent nearly 7,000 containers of weapons to Russia, officials said.
South Korea's defense minister said the containers could hold as many as 3 million 152mm artillery shells, or more than 500,000 122mm rockets, and could carry a mix of both weapons, he said. In the latest estimate, Defense Minister Shin Wok-sik said last week that the number of North Korean shipping containers sent to Russia was 10,000.
Additionally, the White House announced in January that Russia had begun testing ballistic missiles manufactured in North Korea. Arms control experts said debris from a short-range ballistic missile, the Hwasong-11A, was found following months of Russian air strikes on Ukrainian cities, including Kharkiv, in February. North Korea may also be supplying anti-tank missiles, portable surface-to-air missiles, rifles, rocket launchers, mortars and artillery shells, South Korean military officials told reporters in November.
Both Moscow and Pyongyang deny any arms trade, which is prohibited by U.N. sanctions imposed on North Korea.
How important are these weapons?
The Ukraine war is a war of attrition, with Russia and Ukraine trying to outgun each other, firing thousands of artillery shells, missiles and rockets every day, meaning every munition that North Korea provides helps Russia maintain an advantage over Ukraine.
Experts point out that the Hwasong-11A series of missiles in particular are highly accurate and difficult to shoot down.
But at least some of the other weapons appear to be outdated or somewhat ineffective. Asked last fall whether the 152mm shells provided by North Korea would have a significant impact on the battlefield, then-U.S. military chief Gen. Mark A. Milley said he didn't think they would be “definitive.”
“Will it make a big difference? I'm skeptical,” he said shortly before stepping down as chairman of the Joint Chiefs of Staff.
