(CNN) The US government on Wednesday moved to increase economic pressure on North Korea, adding new sanctions that target one individual and three shipping companies in Singapore, China and Russia for violating restrictions on trade with Pyongyang.

The Treasury Department announcement follows criticism from US officials that United Nations members needed to more strictly enforce sanctions against North Korea as part of the effort to get Pyongyang to denuclearize.

US Ambassador to the UN Nikki Haley directly called out Russia and China in July, when she and Secretary of State Mike Pompeo called on other countries to maintain economic pressure on Pyongyang to push the country to denuclearize.

The Treasury Department slapped sanctions on China's Dalian Sun Moon Star International Logistics Trading Co. and Singapore-based affiliate SINSMS Pte. Ltd. for working together to facilitate illicit shipments to North Korea by using falsified shipping documents, such as exports of alcohol, tobacco and cigarette products.

The agency also sanctioned Russia's port service agency, Profinet Pte Ltd, and the company's director general, Vasili Aleksandrovich Kolchanov, a Russian national. The company has provided port services at least six times to DPRK-flagged vessels that have been previously sanctioned, according to the US government.

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