CARACAS (Reuters) – Venezuela held nationwide armed forces exercises on Saturday, calling on civilians to join reserve units to defend against a possible attack after U.S. President Donald Trump warned that a “military option” was on the table for the crisis-hit country.

Trump made the threat two weeks ago and on Friday he signed an order prohibiting dealings in new debt from the Venezuelan government or its oil company, a move to hobble financing that Trump says is fueling socialist President Nicolas Maduro’s “dictatorship.”

“Against the belligerent threats of the United States, all Venezuelans between the ages of 18 and 60 are required to contribute to the integral defense of the nation,” said an announcement broadcast early on Saturday on state television.

Maduro used Trump’s threat to try to energize his political base, broadcasting images of rifle-carrying civilians negotiating obstacle courses and learning hand-to-hand combat. The government created the hashtag #EsHoraDeDefenderLaPatria, which translates as “It’s Time To Defend The Homeland,” to promote the exercises.

TV images showed Venezuelans young and old entering military reserve registration centers. But there was no evidence that registration reached far beyond government employees and Maduro’s Socialist Party loyalists.