The Biden administration has imposed its first sanctions over North Korea's weapons programs following a series of North Korean missile launches, including two since last week.
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 US 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 administration of US 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.
US State Department spokesman Ned Price said Washington 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 UN Security Council resolutions.
It said the State Department had designated Russia-based North Korean Choe Myong Hyon, Russian national Roman Anatolyevich Alar and the Russian firm Parsek LLC for "activities or transactions that have materially contributed to the proliferation of weapons of mass destruction or their means of delivery."
It said Choe Myong Hyon, a Vladivostok-based representative of North Korea's Second Academy of Natural Sciences (SANS), had worked to procure telecommunications-related equipment from Russia.
Four China-based North Korean representatives of SANS-subordinate organisations - Sim Kwang Sok, Kim Song Hun, Kang Chol Hak and Pyon Kwang Chol - and one other Russia-based North Korean, O Yong Ho, were also targeted.
North Korean media said leader Kim Jong Un observed the test of a hypersonic missile on Tuesday, the second in less than a week after he vowed in a New Year speech to bolster the military with cutting-edge technology.
UN resolutions ban North Korean ballistic missile and nuclear tests and impose sanctions.
Wednesday's actions freeze any US-related assets of those targeted and prohibit all dealings with them.