US will not recognise Venezuela election result: State Department

The United States is actively considering oil sanctions on Venezuela and Sullivan said a response to Sunday's vote would be discussed at a G20 meeting in Buenos Aires on Monday.

Venezuelan President Nicolas Maduro was seeking a six-year term in a Sunday election boycotted by the opposition and condemned by foes as the "coronation" of a dictator. Results are expected by late evening.

The G20 meeting, from May 20 to May 21, seeks to provide an opportunity to discuss the contributions and role of the G20 in support of multilateralism and global governance. It will also provide an opportunity to look at ways to promote fair and sustainable development and prepare for the G20 Leaders' Summit due to take place for the first time in South America from November 30 to December 1.