Venezuelan President Nicolas Maduro is going ahead with the inauguration of a powerful new assembly, albeit with a 24-hour delay, even though the British firm hired to handle the vote said the turnout figure given by his government was too high.

President Maduro accused an international voting software firm of being part of a U.S. campaign to stain the results of the country's election of a constitutional assembly.

The technology firm hired to handle the vote, Smartmatic, said in a London news conference that the official figures from the election were "tampered with" to make turnout appear greater than it was.

Maduro told members of the newly chosen constituent assembly Wednesday night that Smartmatic bent to U.S. pressures aimed at casting doubt on the official results announced for Sunday's vote. Smartmatic's CEO said earlier in the day that the government's turnout figures were off by at least 1 million. The nation's electoral council has said more than 8 million people voted, but independent analysts have questioned that number. Maduro said during the meeting Wednesday night that an additional 2 million people might have voted if they hadn't been blocked by barricades put up by anti-government protesters.

Maduro's government has long been threatened by international condemnation led by Washington. "The United States condemns the elections ... for the National Constituent Assembly, which is designed to replace the legitimately elected National Assembly and undermine the Venezuelan people's right to self-determination," U.S. State Department spokeswoman Heather Nauert said in a statement. It threatened further "strong and swift" sanctions on Maduro's government.

CIA Director Mike Pompeo confessed earlier that the agency is working to overthrow the Venezuelan government and has collaborated with two countries in the region – Colombia and Mexico.

Amid months of violent protests and international condemnation, Maduro insists it is the solution to a drawn-out economic and political crisis gripping Venezuela. The assembly was originally due to start work yesterday, but Maduro postponed the launch today in the face of opposition plans for massive protests. He said the reason for the delay was that 35 newly elected members had not yet been officially declared by electoral authorities. Venezuela has been rocked by four months of clashes at anti-Maduro protests that have left more than 125 people dead.