Taoiseach Micheál Martin spoke to US President-elect Joe Biden for more than 20 minutes on Tuesday evening.
During the call, Mr Biden spoke too about his strong desire to visit Ireland during his term as US President.
Mr Martin was forced to leave the Dáil chamber in the Convention Centre hastily in order to take what Transport Minister Eamon Ryan as “an important call”.
According to sources familiar with the call, the exchange between Mr Martin and the successful democratic candidate was described as “very warm” and Mr Biden committed his continued support for the Good Friday Agreement, Mr Biden informed the Taoiseach that he sees Ireland as a “key bridge-builder” in his desire to restore good relations between the US and the EU.
It is understood that Mr Biden told Mr Martin he would immediately sign the Paris Accord after he is sworn in on 20 January.
The Delaware-based President-elect said that he wants to create the conditions for a global economic recovery.
I’ve had a warm and engaging call with US President Elect @joebiden He brings tremendous knowledge & understanding to his new role, and has a great love for his Irish heritage. He underlined his commitment to the Good Friday Agreement & we spoke of importance of multilateralism..
— Micheál Martin (@MichealMartinTD) November 10, 2020
Mr Biden spoke at length about his Irish connections and he was aware of Mayo's win against Roscommon in the Connacht Football Championship last Sunday.
Mr Martin earlier inadvertently tweeted out that he and Mr Biden had had an “excellent call” before the two leaders had spoken.
In a statement, the Government said Mr Martin congratulated President-elect Biden and Kamala Harris on their remarkable election victory.
“In a warm conversation, President-elect Biden recalled his strong Irish roots and his visit to Ireland with his family in 2016. The President-elect reaffirmed his full support for the Good Friday Agreement and they discussed the importance of a Brexit outcome that respects the GFA and ensures no return of a border on the island of Ireland,” the statement said.
“They looked forward to working together bilaterally and across a range of international areas including EU-US relations, the UN - including the Security Council, and on the important global challenges of Covid-19, economic recovery and climate change,” the statement added.
Mr Biden also spoke to British Prime Minister Boris Johnson on Tuesday.
In a statement, a Downing Street spokesman said: "In a call this afternoon the Prime Minister warmly congratulated Joe Biden on his election as President of the United States.
"The Prime Minister also conveyed his congratulations to vice president-elect Kamala Harris on her historic achievement.
I just spoke to @JoeBiden to congratulate him on his election. I look forward to strengthening the partnership between our countries and to working with him on our shared priorities – from tackling climate change, to promoting democracy and building back better from the pandemic.
— Boris Johnson (@BorisJohnson) November 10, 2020
"They discussed the close and longstanding relationship between our countries and committed to building on this partnership in the years ahead, in areas such as trade and security - including through Nato.
"The Prime Minister and president-elect also looked forward to working closely together on their shared priorities, from tackling climate change, to promoting democracy, and building back better from the coronavirus pandemic.
"The Prime Minister invited the president-elect to attend the Cop26 climate change summit that the UK is hosting in Glasgow next year. They also looked forward to seeing each other in person, including when the UK hosts the G7 summit in 2021."
In the Dáil, Sinn Féin leader Mary Lou McDonald said Mr Biden's election was "good for Ireland in many ways".
"He is as we know proud of his Irish roots and without doubt a long-standing friend of Ireland.
"During the presidential election campaign and indeed throughout his time in office he has acted to promote and protect peace, progress and the Good Friday Agreement.
"He comes to the office of president at a time of threat from the British government with Brexit and their refusal to honour agreements looming large."