() President Donald Trump on Monday issued an executive order declaring any country buying oil or gas from Venezuela will pay a 25% “secondary tariff” on trades with the United States.

In a social media post, Trump said Venezuela has been “very hostile” to the U.S. and that countries purchasing oil from Venezuela will be forced to pay the tariff on all U.S. trade starting April 2.

Patrick Duddy, former U.S. ambassador to Venezuela, told “Morning in America” he believes Trump is trying to punish Venezuelan President Nicolás Maduro’s administration and compel compliance with American tariffs.

Duddy said Chevron has been pumping about a fifth of the crude oil Venezuela has produced in the last 10 or so months. While that estimation is down from the total production some decades ago, it is significant and has been “a lifeline” for the Maduro administration, Duddy said.

“I think the other aspect of the sanctions and tariffs that have been imposed earlier on Venezuela specifically is that tariffs imposed, more or less unilaterally, generally don’t work, even as in the case of Venezuela, when the affected elements of the foreign economy are central to their to their GDP,” he said.

Trump said the tariff is a result of Venezuela “purposefully and deceitfully” sending “tens of thousands of high level, and other, criminals, many of whom are murderers and people of a very violent nature” to the U.S.

Trump has pushed for the deportation of Venezuelans he claims are part of the Tren de Aragua gang.

Within two weeks, the U.S. has flown hundreds of immigrants to El Salvador and Venezuela under the Alien Enemies Act of 1798, kicking off a legal battle with federal judge James E. Boasberg, whose order to stop the first round of flights was not carried out.

Trump has accused Venezuela of being “hostile” to America’s repatriation efforts. Maduro later agreed to resume accepting flights from the U.S.

Maduro had paused accepting repatriation flights earlier in March after the Treasury Department pulled Chevron’s license to export Venezuelan oil.

Other reciprocal tariffs are set to begin April 2, including levies against Mexico, Japan, South Korea, Canada, India, China, the European Union.

‘s Anna Kutz contributed to this report.