WASHINGTON, Dec. 18 (Xinhua) -- The Trump administration on Thursday imposed new sanctions on 29 more ships over alleged ties to Iran's shadow fleet, the U.S. State Department announced in a statement.

"Today, the United States is acting to stem the flow of the Iranian regime's revenue used to support terrorism and other illicit activities," said the statement, accusing the sanctioned vessels of engagement "in the covert delivery of hundreds of millions of dollars' worth of Iranian oil and petroleum products."

Among the entities sanctioned is a network of companies and vessels operated by Hatem Elsaid Farid Ibrahim Sakr, an Egyptian businessman, and several companies active in countries including the UAE, India, the Marshall Islands, and Panama, said the statement.

Washington has imposed sanctions on more than 180 ships suspected of connections to the Iranian oil and gas trade since January, local media reported.

For almost four months, the United States has maintained a significant military presence in the Caribbean, much of it off Venezuela's coast, purportedly to combat drug trafficking -- a claim Venezuela has rejected, calling it a pretext for regime change.

It isn't clear whether any of the newly sanctioned vessels transport oil to and from Venezuela.

U.S. President Donald Trump on Tuesday ordered "a total, complete blockade of all sanctioned oil tankers going into and out of Venezuela," stepping up a months-long pressure campaign against Venezuelan President Nicolas Maduro. ■