A U.S. Treasury statement listed 10 companies and six people, including Chinese coal, steel and financial firms, as well as three Russian individuals.
Moscow has fired back at the latest round of USA sanctions targeting Russian interests, as Washington blacklisted one Russian company and four individuals for their alleged dealings with North Korea.
Ten Chinese and Russian companies as well as six individuals are targeted by a new round of USA sanctions aimed at curbing Pyongyang's weapons program.
On Tuesday, the US Treasury revealed it had imposed sanctions on 16 Russian and Chinese nationals and companies for their alleged dealings with North Korea.
In this undated photo distributed Wednesday, Aug. 23, 2017, by the North Korean government, leader Kim Jong Un, center, visits the Chemical Material Institute of Academy of Defense Science at an undisclosed location in North Korea.
"We must continue to isolate the regime, cut off its economic activity and pressure nations, particularly China and Russian Federation, whose companies and citizens help the North generate the resources used to further its aggressive nuclear programme", said Congressman Dan Donovan who serves on the House Committee on Homeland Security and the House Committee on Foreign Affairs.
The 16 affected entities either do business with previously sanctioned companies and people, work with the North Korean energy sector, help it place workers overseas or facilitate its evasion of worldwide financial curbs.
China is pushing back against recent US sanctions relating to North Korea's missile and nuclear programs.
The U.S. Treasury Department said the new sanctions targeted those helping already-designated individuals supporting North Korea's nuclear and ballistic missile programs and its energy trade. "If you support the brutal North Korean regime, there will be a punitive response from the United States", he said.
"However, there are missing elements".
In Dandong, a Chinese border town, AFP found last month that vibrant trade continued despite sanctions - with many Chinese shops continuing to offer jewels made of North Korean gold and silver, which have always been banned from the other side. "In addition, these Chinese networks likely have additional front companies operating on behalf of the network and those were not sanctioned".
China, the main ally of Pyongyang and the recipient of some 90 percent of North Korea's exports, suspended all imports of coal in February in compliance with United Nations sanctions.
Richard Nephew of Columbia University said it appeared the USA government was "exploring what the tolerance is to the use of secondary sanctions".