The Speaker of the US House of Representatives Nancy Pelosi has reiterated that progress with the Northern Ireland peace process cannot be undermined by Brexit.

She is leading a US Congressional delegation, which includes several members of the Friends of Ireland caucus - such as Congressman Richie Neal.

Ms Pelosi addressed the Dáil on Wednesday afternoon, as part of a two-day fact-finding visit to Ireland.

She began by outlining her family's Irish connections - of which she said she has Irish grandchildren, who were baptised in Co Wicklow.

US House Speaker Nancy Pelosi listens as Ceann Comhairle Seán Ó Fearghaíl speaks in the Dáil | Image: Oireachtas screenshot

She spoke about shared history between Ireland and the US: "The Irish were soldiers in the War for Independence - so strong were they of such bravery that a British officer lamented 'We have lost America through the Irish'".

"Irish workers built our canals, ports, railroads, Irish bricklayers built our hospitals and schools".

"Both our nations know the joy of independence; both our countries endured the traumatic experience of civil war, and the satisfaction of rebuilding our nations.

"And it is these mutual experiences that our nations affirmed for each other and to the world our democratic values and commitment to freedom".

An overview of the Dáil chamber ahead of Nancy Pelosi's address | Image: Oireachtas screenshot

"From the crucible of depravation and famine, Ireland has emerged as a confident and ascendant nation on the forefront of innovation in a modern, global economy".

"You have continued to take the lead on peace and the global peacekeeping and humanitarian missions that are filled with and lead by Irish men and women.

"During our visit, we've heard excellent arguments... on why Ireland should sit on the UN Security Council".

On Brexit, Ms Pelosi said: "We treasure the Good Friday accord - not only because of what it has meant for Northern Ireland and for Ireland, that would be reason enough.

"We treasure the Good Friday accord because it is not just a treaty, it is an epic, it is a value, it is an article of faith for us - it is a beacon to the world.

"We treasure the Good Friday accord because of what it says is possible for the entire world, a reason to hope that in every place that dreams, that reconciliation will be possible for them too".

"I've said it before and I'll say it again: we must ensure that nothing happens in the Brexit discussions that imperil the Good Friday accord, including but not limited to the seamless border between the Irish Republic and Northern Ireland.

"Let me be clear: if the Brexit deal undermines the Good Friday accords, there would be no chance of a US-UK trade agreement.

"I say that hopefully that we would not have to face that reality - but I say it as a prediction.

"As you face the challenges posed by Brexit, know that the United States Congress - Democrats and Republicans in the House and in the Senate - stand with you".

U2 singer Bono and his wife Ali Hewson listen to Nancy Pelosi in the Dáil | Image: Oireachtas screenshot

Ms Pelosi also spoke to U2 singer, Bono, who was in the chamber with his wife Ali Hewson.

Calling U2 one of Ireland's "most beloved exports", she said: "We've learnt so much at U2 concerts about what's going on in Ireland" - referring to a Belfast concert attended by David Trimble and John Hume in 1998.

"I take pride as saying I'm one of the Members of Congress who's been to more U2 concerts than anyone - now he's in the audience", she laughed.

"Give my regards to the rest of U2 - The Edge and others", she said.

"From the roots of heritage and history, a modern Ireland has blossomed.

"What a powerful statement that Ireland, steeped in tradition, would be the first nation in all of the world to deliver yes to marriage quality for LGBTQ brothers and sisters.

"Not by a ruling in the courts and not by an act of the legislature, but an overwhelming vote of the Irish people themselves.

"And further the people of Ireland voted to affirm the reproductive rights of women - Ireland shows the true strength of a nation with the confidence to open itself up to new ideas, new people and a new future".