North Korea will send reinforcements to join its troops fighting alongside Russia against Ukraine in the next two months, The New York Times reported on Wednesday, citing a senior U.S. Department of Defense official.

Russia signed a strategic partnership treaty with Iran on Friday that follows similar pacts with China and North Korea. All three countries are adversaries of the United States, and Russia has used its ties with them to help blunt the impact of Western sanctions and boost its war effort in Ukraine.

North Korean troops have been deployed to bolster Russian forces in the Kursk border region with Ukraine, where they are gaining battlefield experience despite initial heavy losses.

These days Russia and North Korea are writing a new battlefield history together. North Korea has dispatched some 12,000 troops to fight in Vladimir Putin’s war against Ukraine. The soldiers are believed to be some of North Korea’s most elite,

Ukrainian forces described a different kind of enemy, fighting with unfamiliar tactics and little option to retreat.