Brexit should be just an “aberration” in the bid to strengthen Northern Ireland’s peace process, US congresswoman Nancy Pelosi has said.

The US House of Representatives speaker visited the Irish border which has become a stumbling block to the UK’s EU withdrawal.

She was greeted by anti-Brexit campaigners during her short stop at the frontier on Thursday morning.

The senior Democrat from California said the US had a vested interest in peace in Northern Ireland which was sealed by the 1998 Good Friday Agreement.

Nancy Pelosi address the media at the border
Nancy Pelosi address the media at the border (Niall Carson/PA)

She said: “We have said that we are guarantors for the Good Friday Agreement because we believe it is fair to both sides – that is why they agreed to it.

“We believe that Brexit should be just an aberration in this discussion as we continue to build and strengthen our peace that was generated by the Good Friday accord.”

Ms Pelosi repeated her assertion that the peace process was a “beacon to the world” and a model for reconciliation.

She said: “Far be it for any of us to want that beacon’s lustre to be dimmed by anything that the Brexit conversation could bring down on the Good Friday accord.”

The congresswoman walked across a “peace bridge” over the River Foyle in Londonderry.

The span was built using EU funds and links primarily nationalist and primarily unionist communities on either river bank.

Ms Pelosi said her border visit was made out of respect for the courage of those who participated in the Good Friday accord.

The US Consulate General in Belfast was established on May 27 1796, by the first American president, George Washington, and is the second oldest continuously operating US consulate in the world.

Ms Pelosi visited Belfast with her daughter more than two decades ago and recalled: “The difference between what we went through then and what we saw in terms of tanks and barbed wire.

“It is about peace, it is about not just what it means to Northern Ireland and Ireland, that would be reason enough for us to be guarantors.”

She expressed pride in the peace process role of president Bill Clinton and talks chairman senator George Mitchell as well as senior congressman Richard Neal.

“What it means to the world to have this example of reconciliation, really ending hundreds of years of conflict, recent thousands of deaths.”

She has repeatedly railed against the prospect of a hard Irish border during her tour of Ireland with congressional colleagues.

Earlier this week she warned that US trade talks with the UK could be endangered if the agreement which largely ended decades of violence was compromised.

The DUP’s opposition to the backstop insurance policy, which would keep Northern Ireland’s regulations aligned with the EU to protect the free-flowing frontier, helped thwart Theresa May’s bid to get her withdrawal deal through Parliament.

Some believe any reimposition of a hard border and checks at the frontier due to a no-deal Brexit could encourage a return to violence, although that is contested by many unionists.

The British Government has said it does not intend to put infrastructure there.

Dermot O’Hara, a spokesman for Border Communities Against Brexit, greeted her at the frontier.

Anti-Brexit protesters at the border
Anti-Brexit protesters at the border (Niall Carson/PA)

He said: “She is saying to the British very clearly that they must respect the Good Friday Agreement, the Good Friday Agreement underwrote the Irish situation here.

“This is a British border here, we want the border to be in the Irish Sea and we appreciate the visit by the delegation and their support for the rights of the Irish people.”

John Boyle, mayor of Derry City and Strabane Council, said it was evident Ms Pelosi was determined to protect the integrity of the agreement.

John Boyle
John Boyle (Steven McAuley/PA)

“They will support us in ensuring it does not impact on that very important agreement which was signed in 1998.”

He said a hard border would be difficult to deal with psychologically.

“Many of us going back generations remember what a hard security border looked like here.”

Joe McHugh, education minister in the Republic and Donegal public representative, said the visit of the third most powerful politician in the US was very important.

He added: “Since Brexit there has been a very loud voice along the border communities and further away from the border communities that we cannot go back to the past, we cannot go back to a border that is going to obstruct the free-flowing movement of goods and people on a day-to-day basis.”