WASHINGTON: The US Treasury placed two entities that either send or help send North Korean workers to Russia on its sanctions blacklist Thursday for involvement in what it called "forced labour."

The Treasury placed sanctions on Korea Cholsan General Trading Corporation, a North Korean company operating in Russia, and Russian construction company Mokran LLC.

The two had "engaged in, facilitated, or been responsible for the exportation of forced labour from North Korea, including exportation to generate revenue for the Government of North Korea or Workers Party of Korea," the Treasury said in a statement.

The two were added to a long list of companies and organizations already blacklisted by the United States for what Washington alleges is an abusive policy of sending North Korean citizens abroad to work and earn foreign exchange, most of which the state allegedly takes.

The sanctions block any assets the named entities might hold under US jurisdiction and ban US companies and individuals from doing business with them, an effort aimed at locking them out of the global financial system.