Speaking alongside Vice President-elect Kamala Harris to CNN's Jake Tapper during their first joint interview since the election, Biden was asked how he can be optimistic about working with the Senate, which is currently controlled by Republicans.
"I say this tactfully," Biden said. "There have been more than several sitting Republican senators who've privately called me and congratulated me."
"And I understand the situation they find themselves in. And until the election is clearly decided in the minds -- where the Electoral College votes, they get put in a very tough position," he added.
Asked if he thinks more GOP senators will publicly recognize his win after the Electoral College votes on December 14, Biden replied: "At least a significant portion of the leadership."
Biden, who served in the Senate for decades before being elected vice president in 2008, said he doesn't know if that will change across the board, noting that many of the senators he served with are no longer in office.
"It's not the same Senate personnel that I knew when I left the Senate. There are only about 35 -- or 30%, 40% that are there when I was in the Senate," he said.
As President Donald Trump has continued to push baseless claims of voter fraud in the weeks following the election, the President's Republican allies have been largely silent on Biden's win. Chief among them is Senate Majority Leader Mitch McConnell, who said last month that Trump is within his rights to make his case in court.
"They call me to say, you know, 'Congratulations, please convey my well wishes to the President-elect, but I can't say that publicly yet,'" Coons told CNN's Alisyn Camerota on "New Day."
CNN's Chandelis Duster contributed to this report.