Venezuela's President Nicolas Maduro warned protesters in Caracas to clear a square they have made their stronghold, or face eviction by security forces.
Plaza Altamira, in upscale east Caracas, has been a focus of anti-government protests and violence during six weeks of unrest around Venezuela that has killed 28 people.
"I'm giving the Chuckys, the killers, just a few hours," Maduro said on Saturday, using the name of a murderous child-doll in a horror film to describe anti-government demonstrators who have made the normally genteel 1940s square a base.
"If they don't retreat, I'm going to liberate those spaces with the security forces."
As dusk fell on Saturday, there were only a handful of protesters in Altamira Square, but some demonstrators were starting to put up barricades of rubbish on other streets in the zone.
Students and other protesters have been using the square, in the pro-opposition Chacao district of Caracas, as a rallying point since a wave of protests started to gather steam in mid-February.
Most nights around dusk, a hard core of several hundred demonstrators has been fighting police and army lines there, in an attempt to access a nearby highway and block traffic.
At a military rally, Maduro also alleged that right-wingers in the US State Department and Pentagon were recommending extreme measures against Venezuela, including sanctions and even his assassination.
"President [Barack] Obama, if this message reaches you, you should know that it would be the worst mistake of your life to sign the authorisation of the assassination of President Nicolas Maduro," he said in a speech recalling his predecessor Hugo Chavez's spats with the United States.
US antipathy to the socialist government has been in evidence since the start of Chavez's 1999-2013 rule, not least in Washington's quick recognition of a brief 2002 coup against him.
Chavez died from cancer last year, with his protégé Maduro, a 51-year-old former bus driver, winning a vote to replace him.
Maduro says he has seen off a "coup" attempt, and he does not look in danger of being toppled, with the military apparently still behind him.