Venezuela's opposition has said it will not hold talks with the government on ending the country's political and economic crisis without a full recount in regional elections it says were rigged.
President Nicolas Maduro claimed victory in Sunday's vote - which opinion polls had put the opposition on track to easily win.
Mr Maduro's candidates took 17 governorships, against five for the opposition, in Sunday's nationwide poll, according to the pro-government electoral board.
Leaders of the opposition Democratic Unity coalition demanded an audit after citing a litany of abuses, including multiple voting, state food handouts on the day of the poll, forced attendance at gunpoint and suspicious phone and power outages.
The opposition fell short of offering detailed evidence of outright fraud, however, and there were no conventional foreign observer missions to verify claims of vote-rigging.
The United States has said the elections were neither free nor fair.
"We condemn the lack of free and fair elections yesterday in Venezuela. The voice of the Venezuelan people was not heard," State Department spokeswoman Heather Nauert said.
"Our previously stated concerns were unfortunately realised: lack of independent, credible international observers; lack of technical audit for the National Electoral Council's tabulation; last minute changes to polling station locations without public notice; manipulation of ballot layouts; and limited availability of voting machines in opposition neighbourhoods."
The Trump administration has already imposed sanctions on Mr Maduro and top officials.
