By Matt Spetalnick and Phil Stewart
WASHINGTON (Reuters) -The Biden administration said on Monday that electoral manipulation had stripped Venezuelan President Nicolas Maduro's claim of reelection victory of "any credibility," and Washington left the door open to fresh sanctions on the OPEC nation.
Senior U.S. officials, briefing reporters on Sunday's election, sharpened Washington's response to the disputed vote, in which Venezuela's electoral authority declared Maduro had won a third term, extending 25 years of socialist party rule.
Independent exit polls pointed to a landslide opposition win.
The U.S. and a number of other governments cast doubt on the official vote count. Maduro's opposition rival, Edmundo Gonzalez, asserted that he was the true winner.
The U.S. officials, speaking on condition of anonymity, amplified public demands by President Joe Biden's senior aides that Maduro publish a detailed tabulation of votes and said a failure to do would leave the international community unwilling to accept the announced outcome.
The officials did not unveil any new punitive measures but said Washington would assess its sanctions policy toward Venezuela based on whatever actions Maduro took going forward.
"We are faced with potentially a new scenario," one official said. "We are going to take that into account as we map forward where we may head with respect to sanctions toward Venezuela."
Washington, which rejected Maduro's 2018 reelection as a sham, broadly eased sanctions on Venezuela's oil industry last October in response to a deal between Maduro and opposition parties. But in April the U.S. reimposed the sanctions, accusing Maduro of reneging on electoral commitments.
"By engaging in repression and electoral manipulation, and by declaring a winner without the detailed precinct by precinct polling results ... Maduro representatives have stripped the supposed election results they announced of any credibility," a U.S. official said.
Speaking earlier in Tokyo, U.S. Secretary of State Antony Blinken said: "We have serious concerns that the result announced does not reflect the will or the votes of the Venezuelan people."
Maduro early on Monday reiterated his campaign assertion that Venezuela's electoral system is transparent.
White House spokesperson John Kirby said the U.S. would withhold judgment until it gets further information but would then "respond accordingly."
U.S. COORDINATES INTERNATIONAL RESPONSE
The U.S. officials did not offer many specifics of electoral misconduct it believes Maduro's side committed.
But one official said the electoral commission's announcement "does not track with data that we've received through quick-count mechanisms and other sources" and appeared at odds with how Venezuelans voted.
The officials said the U.S. was coordinating with regional allies on a response and would also work with international partners on potential consequences for Maduro's government.
A senior U.S. official said the administration was in contact with Brazil and other Latin American governments concerned about the political situation in Venezuela.
Biden will speak with Brazilian President Luiz Inácio Lula da Silva on Tuesday afternoon, the White House said.
They defended the Biden's administration's decision last year to re-engage with Maduro following the Trump-era "maximum pressure" campaign, despite the Venezuelan leader's history of failing to make good on his political promises.
Sunday's election, one official said, was a sweeping call for change from Venezuelan voters and would put the opposition in a better position to negotiate with Maduro.
But Republican U.S. Senator Marco Rubio, a harsh Maduro critic, chided the Democratic administration in a post on X, calling it "the latest example of how our enemies have suckered Biden and (Vice President Kamala) Harris repeatedly."
Analysts have suggested that a Maduro reelection or post-election upheaval could spur more Venezuelans to leave the country and head for the U.S.-Mexico border.
With immigration already a hot-button issue in the U.S. presidential campaign, that could create new problems for Harris, seen as the likely Democratic nominee after Biden ended his reelection bid on July 21.
(Reporting by Matt Spetalnick, Jasper Ward and Phil Stewart; additional reporting by Doina Chiacu and Trevor Hunnicutt; Editing by Rosalba O'Brien and Michael Perry)