"The president has been crystal clear and incredibly consistent. Military action is possible. If that's what's required, that's what the United States will do," Pompeo said on Fox Business Network.

Pompeo said the US would prefer a peaceful transition of power, with President Nicolas Maduro leaving and new elections held to choose new leaders.

"But the president has made clear in the event that there comes a moment -- and we will all have to make decisions about when that moment is and the president will ultimately have to make that decision -- he's prepared to do that if that's what's required."

In a separate interview with CNN, National Security Advisor John Bolton said Pompeo would be speaking later today with Russian Foreign Minister Sergei Lavrov to discuss the situation.

Bolton and Pompeo have accused Russia and Cuba of standing in the way of a change in the regime in Caracas.

Pompeo said Tuesday that Maduro was set to leave the country for Cuba but apparently was talked out of it by the Russians.

"The Russians like nothing better than putting a thumb in our eye," Bolton said. "They're using the Cubans as surrogates. They'd love to get effective control of a country in this hemisphere."

"It's not ideological, it's just good old fashioned power politics. That's why we have the Monroe doctrine which we're dusting off in this administration, why the president indicated last night that the Cubans better think long and hard about what their role is," he added.

The Monroe doctrine is a 19th century US policy opposing interference in the western hemisphere by European powers, which later was invoked to justify US intervention in Latin America.