The illicit cigarette trade has reportedly generated more than US$1 billion in annual revenue for the Pyongyang regime, according to the department.
The U.S. Treasury Department said on August 15 that it was taking actions against three shipping companies based in China, Singapore, and Russia, as well as the head of the Russian shipping firm, Profinet Pte.
Earlier in the month, the United Nations has released a report claiming the Pyongyang has not stopped its nuclear and missile programs "and continued to defy Security Council Resolutions through a massive increase in illicit ship-to-ship transfers of petroleum products, as well as through transfers of coal at sea during 2018", the document read as cited by Reuters.
The result of such sanctions is that any property or interests in property of the persons involved must be blocked, and the United States is generally prohibited from dealing with any of the persons.
They are accused of helping North Korea evade worldwide sanctions by re-routing exports and imports through Chinese and Russian ports.
When asked for comment, Liang Ye, a legal representative of Dalian Sun Moon Star International Logistics Trading, said the matter was still unclear and that the Chinese company had not received any notification.More news: Pakistani lawmakers elect Imran Khan as new PM
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The latest sanctions were imposed amid predictions that U.S. Secretary of State Mike Pompeo will soon visit North Korea again after Washington and Pyongyang held working-level talks at the inter-Korean border village of Panmunjeom over the weekend.
Such commentaries are not statements or official positions, but can be read as a reflection of government thinking.
He only helped prepare documents for the vessels, he said, and was not involved in trading anything.
It said the Russian firm and its director, Vasili Aleksandrovich Kolchanov, provided port services at least six times to North Korean-flagged vessels engaged in sanctions busting oil shipments.
As the Trump White House refuses to ease sanctions on the regime until it gives up its nuclear weapons, North Korea's state newspaper, the Rodong Sinmun, urged the South again on Thursday to distance itself from Washington, at one point threatening "irreversible results".
"It's not our concern who fuels the vessels, who sells that fuel, who they buy the cargo and oil products from", he said.