In view of the new sanctions, he said, "U.S. statements about a desire to stabilize bilateral ties sound particularly unconvincing".
The Trump administration has unveiled new sanctions against China and Russian Federation as part of an escalation to curb North Korea's nuclear and missile programs.
Ten Chinese and Russian companies as well as six individuals were named, some of whom are trading coal, oil and mineral resources with North Korea.
The US Treasury Department will soon impose economic sanctions on Russian and Chinese companies, along with individuals conducting business with North Korea. Mnuchin said the sanctions will help to isolate North Korea from the finances necessary to further their nuclear program. Treasury Secretary Mnuchin also noted the U.S.is "taking actions consistent with United Nations sanctions to show that there are consequences for defying sanctions and providing support to North Korea, and to deter this activity in the future".
Reacting to the sanctions, Russian Deputy Foreign Minister Sergey Ryabkov issued a statement expressing disappointment, and warning Washington that Russia was working on a response.
Jonathan Pollack, a senior fellow at the Brookings Institution and an expert on the Korean Peninsula, said that despite the UN Security Council resolutions, China and the U.S. disagree sharply about the sanctions process and on how Beijing and Washington view the available tools to constrain the DPRK's ability to access foreign currencies. But he voiced hope that the United States will eventually realize that such sanctions won't work.
Iron ore arrivals from North Korea in July also sank to their weakest since February, while China's gasoline exports to the isolated state hit their lowest since January 2016.
The sanctions list includes the Russian company Gefest-M LLC and its general director Ruben Kirakosyan. The Chinese government came out strongly against Washington's move, saying it's opposed to unilateral sanctions outside the framework of the UN Security Council.
"These sanctions are illegal in themselves, because the only thing recognized by global law is the sanctions of the UN Security Council", Klimov told Interfax.
"We strongly urge the USA to immediately correct its mistake, so as not to impact bilateral cooperation on relevant issues", the spokesperson said, as quoted by the Financial Times.
The DoJ alleges that the two companies violated the worldwide sanctions against North Korea and indirectly supporting its missile and nuclear weapons programs.