The United States remains concerned about growing military cooperation between North Korea and Russia, a state department spokesperson said Monday, adding the U.S. will continue to implement all existing sanctions on the two countries.

The department spokesperson, Matthew Miller, also called on Pyongyang to stop its pursuit of illegal weapons programs and engage in dialogue.

"Obviously, we have seen close cooperation between Russia and North Korea," the spokesperson told a daily press briefing when asked about military cooperation between Pyongyang and Moscow.

"We have made clear our concerns about cooperation between Russia and North Korea. We have made clear our concerns about North Korea seeking to assist Russia in its aggression in Ukraine, and we will continue to make those concerns clear and we will continue to enforce all of our sanctions," added Miller.

His remark comes after Russian Defense Minister Sergei Shoigu visited Pyongyang late last month, which many North Korea watchers suggest will lead to an increase in military cooperation between the two countries.

John Kirby, National Security Council coordinator for strategic communications, has said the North appears to be considering providing military support to Russia, including munitions to be used in Russia's war against Ukraine.

North Korean leader Kim Jong-un reportedly visited major weapons factories last week in a move that Seoul officials said was aimed at calling for efforts to boost the country's production and exports of weapons.

"I certainly wouldn't try to speak for him or explain his actions," Miller said when asked about Kim's recent visits to weapons factories.

"But I would say, as we have said before, that we would continue to condemn the missile launches that they have tested in recent weeks. We continue to condemn their pursuit of a nuclear weapon and would hope that they would engage in talks, which they have shown, so far, no inclination to do," he added. (Yonhap)