WASHINGTON (Reuters) -U.S. President Donald Trump’s administration on Thursday imposed sanctions on a third Chinese independent – or “teapot” – oil refinery, and port terminal operators in China for purchases of Iranian oil.

The U.S. Treasury designated the Hebei Xinhai Chemical Group Co refinery and three port terminal operators in China.

It was the latest independent Chinese refinery targeted by the Trump administration as it steps up efforts to cut off Iran’s export revenue and seeks to pressure Tehran into a deal to curb its nuclear program.

“So long as Iran attempts to generate oil revenues to fund its destabilizing activities, the United States will hold both Iran and all its partners in sanctions evasion accountable,” the U.S. Treasury said in a statement.

Previous sanctions imposed on two small Chinese refiners for buying Iranian oil have created difficulties in receiving oil, leading them to halt purchases of crude and sell product under other names, sources familiar with the matter said.

Those sanctions have also begun to deter other, larger independent Chinese refiners from buying Iranian crude, three of the sources said.

(Reporting by Timothy Gardner and Ishmail Shakil; editing by Mark Heinrich)