"The Constitution constrains me from claiming unilateral authority to determine which electoral votes should be counted and which should not," Pence said in a statement released as a joint session of Congress began to certify the Electoral College votes from the Nov. 3 election.
Despite saying he did not believe he had the power to accept or reject electoral votes, Pence welcomed efforts by U.S. lawmakers to raise objections about alleged "voting irregularities."
Pence, under intense pressure by Trump to hold up the certification of Biden's victory, told Congress in a letter that he would do his duty to ensure concerns about the election received a "fair and open hearing."
"When disputes concerning a presidential election arise, under federal law, it is the people's representatives who review the evidence and resolve disputes through a democratic process," said Pence, who is presiding over a joint session of Congress to certify the election results.
The statement was released as Trump urged Pence at a rally in Washington to decline to certify the Electoral College results.
Later, the top Republican in Congress also delivered a stinging rebuke to Trump loyalists in his party who have objected to final certification of Biden's presidential victory, warning such a move could prompt a "death spiral" for U.S. democracy.
"If this election were overturned by mere allegations from the losing side, our democracy would enter a death spiral -- we'd never see the whole nation accept an election again," said Senate Majority Leader Mitch McConnell, in some of his most forceful floor remarks in years.
"The voters, the courts, and the states have all spoken. If we overrule them, it will damage our republic forever," McConnell said, minutes after Republicans objected to certification of Arizona's Electoral College votes for Biden, citing unproven allegations of election fraud.
With supporters of Trump gathering around the Capitol, more than a dozen Republican senators and more than 100 Republican House members have said they will object to the count from as many as six battleground states. They are echoing Trump’s false claims of widespread fraud.
Their efforts are almost certain to fail as many Republicans have said they will oppose the objections. But the session is expected to last into the night on Wednesday as the House and Senate must consider each objection separately and vote on whether to sustain it.
Biden won the Electoral College 306-232. He is set to be inaugurated on Jan. 20.
