Republican leader Mitch McConnell congratulates Joe Biden on presidential win

President Donald Trump’s efforts to overturn the results of the US presidential election hit another snag on Tuesday as a growing number of senators from his party acknowledged and even congratulated president-elect Joe Biden on his win.

The highest-ranking Republican in the US Senate, Majority Leader Mitch McConnell, symbolically broke with Mr Trump by offering his congratulations to Mr Biden. Speaking from the Senate floor, 38 days after the election was called in favour of Mr Biden, Mr McConnell acknowledged his party’s defeat in the race for the White House.

“The electoral college has spoken. So, today, I want to congratulate president-elect Joe Biden,” Mr McConnell said. "Our country has officially a president-elect and a vice president-elect.”

The electoral college officially confirmed Mr Biden's and vice president-elect Kamala Harris's win on Monday, certifying the 306-232 margin of victory. Congress will meet on January 6 in the final step to confirm the results and to announce the inauguration of Mr Biden and Ms Harris on January 20.

Mr McConnell was criticised on Monday for waiting so long to acknowledge Mr Biden’s victory. Chris Coons, a Democrat senator, told CNN on Tuesday that it was “gravely concerning” that Russian President Vladimir Putin congratulated Mr Biden before Mr McConnell. The Kremlin issued its congratulations early on Monday.

More Republicans in the Senate recognised Mr Biden's win in the past 24 hours. These include senators John Cornyn, Roy Blunt, John Thune, Lamar Alexander and Shelley Moore Capito. Even Lindsey Graham, a senator and ardent supporter of Mr Trump who embraced some of his allegations about election fraud without presenting evidence, publicly recognised Mr Biden's win and said the two have already spoken.

"There's things we can do together, some things that we can't do together. It was a very pleasant conversation," Mr Graham said.

A handful of Republican senators congratulated Mr Biden early after the election was called on November 7, such as Susan Collins, Mitt Romney, Pat Toomey, Lisa Murkowski and Ben Sasse.

Mr Trump has neither conceded the race nor expressed his intent to attend Mr Biden’s inauguration.

"I don't want to talk about that," he told Fox News when asked if he would be attending the ceremony. His campaign has lost 59 legal challenges disputing the election results.