Russian President Vladimir V. Putin will travel to North Korea for a two-day visit starting Tuesday to meet with a major arms supplier for his war against Ukraine.
As the war dragged on, Russia found itself in desperate need of conventional weapons, including artillery shells, which North Korea could provide.
Here's some background on what's happened so far and why it matters.
What do we know about previous weapons shipments?
The United States first accused North Korea of selling artillery to Russia as early as September 2022, seven months into the war. North Korea denied the allegations at the time.
Then, last August, the White House warned that Putin and the North Korean leader, Kim Jong-un, were holding arms negotiations, and in September, Kim visited Putin in eastern Russia. A few weeks later, U.S. officials said North Korea had shipped more than 1,000 containers of weapons to Russia for use in the war in Ukraine. By March, officials said, North Korea had sent nearly 7,000 containers of weapons to Russia.
If filled with 152-millimeter artillery shells, the containers could carry up to three million shells, South Korea's defense minister said. Or, if filled with 122-millimeter rockets, they could hold more than half a million shells . They might even have contained a mix of both weapons, he said. In his latest estimate, Minister Shin Wok-sik last week put the number of containers shipped from North Korea to Russia at 10,000.
Additionally, the White House said in January that Russia had begun firing ballistic missiles made in North Korea. Arms control experts said fragments of the Hwasong-11A short-range ballistic missile were found following Russian airstrikes on Ukrainian cities for months, including Kharkiv in February. North Korea could also provide anti-tank missiles and man-portable surface-to-air missiles, as well as rifles, rocket launchers, mortars and projectiles, South Korean military officials told reporters in November.
Both Moscow and Pyongyang deny the arms trade, which is banned under sanctions imposed by the United Nations on North Korea.
How important are these weapons?
The war in Ukraine is a war of attrition, with Russia and Ukraine trying to outdo each other, firing thousands of artillery shells, missiles and rockets every day. This means that all the munitions supplied by North Korea help Russia maintain an advantage over Ukraine.
The Hwasong-11A series missiles, in particular, have a high degree of accuracy and are difficult to shoot down, experts said.
But at least some of the other weapons are believed to be old or otherwise somewhat ineffective. Last fall, the top U.S. military officer at the time, Gen. Mark A. Milley, said he doubted it would be “decisive” when asked whether the 152-millimeter projectiles supplied by North Korea would have much impact on the battlefield.
“Would there be a huge difference? I'm skeptical about it,” he said shortly before resigning as chairman of the Joint Chiefs of Staff.