The Treasury Department said that it blacklisted Russia-based company Volasys Silver Star, China-based China Silver Star and its CEO Jong Song Hwa for violating US sanctions.
China Silver Star's North Korean CEO, Jong Song Hwa, was also designated.
The revenue raised by those companies helps the North Korean government skirt US sanctions, which are meant to pressure the country to denuclearize.
Mnuchin warned companies across the globe "to take precautions to ensure that they are not unwittingly employing North Korean workers for technology projects".
The United States on Thursday criticized Russian Federation for interfering with the process of publishing a U.N. report on North Korea sanctions that was due last week.
Russian Federation then also blocked a United States demand that two of the nation's shipping companies and six of their vessels be sanctioned over oil shipments to North Korea.More news: Seahawks host linebacker Mychal Kendricks on free agent visit
The Trump administration has sought to ramp up pressure on Kim to strike a deal to halt North Korea's nuclear program in part by penalizing Chinese and Russian firms that the increasingly isolated country depends on to keep its economy afloat. White House officials acknowledge there's been no progress on denuclearization, even as President Donald Trump considers a second summit with North Korea leader Kim Jong Un.
The Security Council is scheduled to meet on September 17 to discuss implementation of sanctions on North Korea at Washington's the request. North Korea has however given no indication it is willing to give up its weapons unilaterally, as the Trump administration has demanded.
"This is a risky precedent and a stain on the important work of the Panel", Haley said, calling for the initial version of the report - dating from early August - to be published.
United Nations diplomats familiar with discussions said Russian Federation was angered that the panel used a lot of USA intelligence in the initial report that Moscow claimed was incorrect. "The full implementation of U.N. Security Council resolutions remains mandatory for all member states - including Russian Federation".
Speaking on condition of anonymity, one diplomat said the amended report removed some references to Russians accused of breaching North Korea sanctions.
Haley has called for the original report to be released by the 15-member Security Council, which must agree by consensus on whether to publish the findings.