North Korea acknowledged for the first time Monday that it had provided troop reinforcements to aid Russia in its war on Ukraine.

North Korea confirmed for the first time on Monday that it has sent troops to fight for Russia in the war with Ukraine under the order of leader Kim Jong-un and made an important contribution to the liberation of Russian territory occupied by Ukraine.

The Trump administration has been trying to broker a peace deal between Ukraine and Russia to halt the three-year conflict.

The outcome of a push by President Trump’s administration to swiftly end the fighting remains unclear, clouded by conflicting claims and doubts about how far each side might be willing to compromise amid deep hostility and mistrust.

U.S. Secretary of State Marco Rubio said on Sunday that a peace deal between Russia and Ukraine needs to happen soon, adding that the Trump administration will spend the coming week trying to determine whether to continue as a mediator.