Nov. 21 (UPI) — President Donald Trump imposed sanctions on several North Korean fishing firms and Chinese trading companies on Tuesday, the Treasury Department said.

One individual, 13 entities and 20 vessels were sanctioned as part of an effort to pressure North Korean leader Kim Jong Un to halt the country’s nuclear program.

“These designations include companies that have engaged in trade with North Korea cumulatively worth hundreds of millions of dollars. We are also sanctioning the shipping and transportation companies, and their vessels, that facilitate North Korea’s trade and its deceptive maneuvers,” Treasury Secretary Steven Mnuchin said.

Three of the Chinese trading companies exported roughly $650 million in goods to North Korea and imported more than $100 million, including notebook computers, coal, iron and other minerals.

Dandong Dongyuan Industrial, another Chinese firm, exported more than $28 million in motor vehicles, electrical machinery and other items associated with nuclear reactors to North Korea, while another organization was designated for exporting workers from North Korea.

None of the firms sanctioned is traded publicly.

The sanctions come after Trump announced plans to re-designate North Korea as a state sponsor of terrorism on Monday joining Iran, Sudan and Syria.

The designation prevents North Korea from receiving U.S. foreign assistance, bans defense exports and sales, and allows the United States to punish people or countries who trade with the country.