The United States is pushing for a United Nations Security Council statement expressing full support for Venezuela's National Assembly as the country's "only democratically elected institution," but Russia is expected to block the move, diplomats say.
The council will meet on Saturday at the request of the United States after Washington and a string of countries in the region recognised Venezuelan opposition leader Juan Guaido as head of state and urged President Nicolas Maduro to step down.
US Secretary of State Mike Pompeo and Venezuela's Foreign Minister Jorge Arreaza, along with several other ministers, are due to address the 15-member body.
Ahead of the public meeting, the United States circulated a draft Security Council statement.
The draft, seen by Reuters, said: "As conditions in the Republic of Venezuela continue to deteriorate, the Security Council expresses its full support for the National Assembly as Venezuela's only democratically elected institution."
If the council backed the statement, it would effectively recognise Guaido - who is head of the National Assembly - as Venezuela's head of state.
Guaido declared himself the country's interim president on Wednesday.
However, Russia's UN Ambassador Vassily Nebenzia said on Friday that Moscow would oppose a US push for the Security Council to back Guaido as interim president.
Council statements must be agreed by consensus.
Before Washington circulated the draft statement to council members late on Friday, Nebenzia told Reuters: "That will not pass ... For us nothing changes."
The draft statement also "calls for the immediate start of a political process that leads to free, fair and credible elections with international electoral observation in the shortest possible time".
During Saturday's Security Council meeting, Pompeo will urge council members and other countries to recognise Guaido, the State Department said in a statement on Friday.
