The U.S. imposed sanctions Friday on six high-ranking members of the Venezuelan security forces in response to the blocking of humanitarian aid convoys last week. The Trump administration also revoked the visas of other officials and their relatives in an ongoing effort to pressure President Nicolas Maduro into leaving office.

The visa revocations are intended to punish those who have flourished amid the country’s dire economic crisis, Elliott Abrams, the U.S. envoy to Venezuela, told reporters. “Maduro supporters that abuse or violate human rights, steal from the Venezuelan people or undermine Venezuela’s democracy are not welcome in the United States,” he said.

The measures are the latest by the Trump administration to increase international pressure on Maduro. Maduro's re-election last year is seen as illegitimate, and Trump has thrown his weight behind opposition leader Juan Guaido, who has been recognized by the U.S. and 50 other governments as interim president.