President Donald Trump threatened to level a full embargo on Cuba if they continued to assist Venezuela Dictator Nicolás Maduro on Tuesday.

“If Cuban Troops and Militia do not immediately CEASE military and other operations for the purpose of causing death and destruction to the Constitution of Venezuela, a full and complete embargo, together with highest-level sanctions, will be placed on the island of Cuba,” Donald Trump wrote on Twitter.

Opposition leader and recognized president Juan Guaido of Venezuela urged for an uprising against Maduro as the United States voiced support for their effort. Armed troops clashed with Venezuelan citizens rising against Maduro.

“Hopefully, all Cuban soldiers will promptly and peacefully return to their island!” Trump wrote.

Cuba denied having soldiers in Venezuela, as Maduro’s future continues to be uncertain.

Secretary of State Mike Pompeo said Maduro had been prepared to leave the country on Tuesday morning, but Russia urged him to remain.

“They had an airplane on the tarmac. He was ready to leave this morning, as we understand it. Russians indicated he should stay,” Pompeo said in an interview with CNN.