U.S. National Security Advisor John Bolton said on Thursday that the toughest sanctions against Venezuela's Maduro government are "yet to come."
"As President Trump clearly stated, the toughest sanctions are yet to come," he tweeted.
Noting that the Maduro government officials "will be strangled financially," Bolton said that "the window is closing."
U.S. President Donald Trump threatened on Tuesday that "we really haven't done the really tough sanctions yet" against the Venezuelan government.
The U.S. Treasury Department so far has slapped six rounds of sanctions since January to pile up pressure on the nation's President Nicolas Maduro. On Tuesday, the Treasury sanctioned a Venezuelan gold mining company and its leader, accusing them of supporting Maduro.
The Trump administration recognized Juan Guaido as the nation's "interim president" on Jan. 23, days after Maduro was inaugurated for a second term as Venezuelan president.
Earlier on Thursday, Bolton criticized via Twitter the Venezuelan government for its reportedly arrest of Roberto Marrero, the aide of the opposition leader Guaido.
The alleged arrest "will not go unanswered," Bolton said. "He should be released immediately and his safety guaranteed."
In response to Washington's support for Guaido, Maduro has announced he was severing "diplomatic and political" ties with the United States.
