President Donald Trump is threatening a “full and complete embargo” and sanctions on Cuba if its troops do not “immediately” cease operations in Venezuela.

Trump’s Twitter missive to the longtime U.S. foe comes amid his swift embrace of a Venezuelan opposition effort to spark a military uprising against embattled President Nicolas Maduro.

Cuba is among Maduro’s staunchest backers amid a U.S.-led effort to recognize opposition leader Juan Guaido as the nation’s legitimate president.