The U.S. State Department has reportedly expressed concern about North Korea’s involvement in Russia’s war against Ukraine, calling for an end to the deployment of North Korean troops and any support Russia provides to the North in return.

Reuters said the department made the comments Monday, hours after North Korea confirmed for the first time having deployed troops to assist Russia. 

A spokesperson for the State Department reportedly told Reuters that Washington remains concerned about North Korea’s direct involvement in the Russia-Ukraine war, saying North Korea and other third countries have perpetuated the war and bear responsibility.

The North’s state Korean Central News Agency said Monday that the country’s leader, Kim Jong-un, made the decision to deploy troops under the comprehensive strategic partnership treaty he signed with Russian President Vladimir Putin last year.

Russia confirmed on Saturday that North Korea has deployed troops to support Russia in its war against Ukraine.