The US Treasury Department on Thursday slapped sanctions on a Chinese bank over illicit activities in North Korea, including facilitating the production of weapons of mass destruction.

Bank of Dandong which "acts as a conduit for illicit North Korean financial activity, is a foreign bank of primary money laundering concern," and will be severed from the US financial system, the Treasury said in a statement.

Treasury Secretary Steven Mnuchin said the move was not targeted at the Chinese government.

"This is not directed at China, this is directed at a bank," he told reporters.