The United States and Russia traded warnings against interfering in Venezuela on Wednesday, a day after U.S. Secretary of State Mike Pompeo accused Moscow of stopping President Nicolas Maduro from leaving the country.

Russian Foreign Minister Sergei Lavrov told Pompeo by phone that further "aggressive steps" in Venezuela would be fraught with the gravest consequences, the Russian ministry said.

"The Russian side underlined that interference by Washington in the internal affairs of a sovereign state and threats towards its leadership was a flagrant breach of international law," the ministry said.

The U.S. State Department said Pompeo urged Russia in the call to stop supporting Maduro. He also "stressed that the intervention by Russia and Cuba is destabilizing for Venezuela and for the U.S.-Russia bilateral relationship," it said.

On Tuesday, Pompeo accused Russia of intervening to persuade Maduro to abandon a plan to leave the country following a call by opposition leader Juan Guaido for Venezuela's military to help him oust Maduro.

Russia rejected that allegation on Wednesday, with foreign ministry spokeswoman Maria Zakharova calling it "fake news."