Russia has condemned foreign powers for backing a Venezuelan opposition leader who declared himself interim president, calling it a bid to "usurp power".
Moscow said that the move violated international law and was a "direct path to bloodshed".
Juan Guaidó declared himself interim leader on Wednesday and was recognised by the US and several other nations.
President Nicolás Maduro, who also won support from some countries, has broken off diplomatic relations with the US.
Mr Maduro took office in 2013 after the death of Hugo Chávez and was sworn in for a second term this month after elections last May that were marred by an opposition boycott and widespread claims of vote-rigging.
How has the diplomatic spat flared?
There was a major difference of opinion after President Donald Trump responded to Mr Guaidó's declaration by recognising him as the new head of state and calling on others to follow suit.
Seven South American nations, Brazil, Colombia, Chile, Peru, Ecuador, Argentina and Paraguay, as well as Canada, backed the call.
French President Emmanuel Macron stopped short of recognition, calling for democratic elections.