All major US networks called the 2020 presidential election for Biden after he took Pennsylvania on Saturday. Getty

A number of prominent Irish politicians were among the first world leaders to congratulate President-elect Joe Biden after all major US networks called the presidential race in his favor. 

Taoiseach Micheál Martin took to Twitter moments after the race was called for Biden to congratulate the incoming President, calling him a "true friend of Ireland."

The Taoiseach also appeared to lay the early groundwork for a presidential visit to Ireland in his congratulatory tweet. 

"I want to congratulate the new President Elect of the USA @JoeBiden
 Joe Biden has been a true friend of this nation throughout his life and I look forward to working with him in the years ahead. I also look forward to welcoming him back home when the circumstances allow!" 

Meanwhile, Tanáiste Leo Varadkar also congratulated Biden and running mate Kamala Harris, echoing Micheál Martin by inviting Biden to Ireland for a state visit. 

"Congratulations @joebiden and @kamalaharris. Our world needs American leadership and true American values," Varadkar said on Twitter. "We know you can give it. Hope you can both make it to Ireland soon." 

Sinn Féin President Mary Lou McDonald also extended her best wishes to the President-elect, commending him for all the work he has done to promote Irish interests in US politics. 

"Joe Biden is of course proud of his Irish roots and a long-standing friend of Ireland," McDonald said in a video posted on Sinn Féin's Twitter account. "During the election campaign and throughout his time in office, he has acted to promote and protect peace, progress and the Good Friday Agreement." 

Biden, meanwhile, has gone viral on social media for his response to a BBC correspondent who asked for a short interview earlier in Biden's campaign. 

The clip, taken from January 2020, features BBC New York correspondent Nick Bryant asking Biden for a "quick word for the BBC". 

"The BBC?" Biden laughed. "I'm Irish." 

The clip has been viewed more than 1.8 million times on Twitter alone.