The Biden administration on Wednesday imposed its first sanctions over North Korea’s weapons programs.

The sanctions targeted six North Koreans, one Russian and a Russian firm Washington said were responsible for procuring goods for the programs from Russia and China.

The U.S. Treasury said the steps aimed both to prevent the advancement of North Korea’s programs and to impede its attempts to proliferate weapons technologies.

The United States also proposed that five of those individuals also be blacklisted by the United Nations Security Council, which would need consensus agreement by the body’s 15-member North Korea sanctions committee.

The administration of U.S. President Joe Biden has sought unsuccessfully to engage Pyongyang in dialogue to persuade it to give up its nuclear bombs and missiles since taking office in January last year.

U.S. State Department spokesman Ned Price said the United States remained committed to pursuing diplomacy with North Korea.

What we have seen in recent days only underscores our belief that if we are going to make progress, that we will need to engage in that dialogue, he told a regular news briefing.

The Treasury Department said the sanctions followed six North Korean ballistic missile launches since September, each of which violated U.N. Security Council resolutions.