The Speaker of the US House of Representatives, Nancy Pelosi, has described Britain's moves to unilaterally discard the Northern Ireland Protocol as "deeply concerning".
She restated her view that the US Congress would block any US-UK trade deal if the Good Friday Agreement was damaged by changes to the Northern Ireland Protocol.
"If the United Kingdom chooses to undermine the Good Friday Accords, the Congress cannot and will not support a bilateral free trade agreement with the United Kingdom," she said.
The Good Friday Accords are the bedrock of peace in Northern Ireland and a beacon of hope for the world. Ensuring there is no physical border between the Irish Republic and Northern Ireland is necessary for upholding this landmark agreement, which transformed Northern Ireland.— Nancy Pelosi (@SpeakerPelosi) May 19, 2022
In remarks delivered during her regular weekly news conference, Speaker Pelosi said: "The Good Friday Accords are the bedrock of peace in Northern Ireland and a beacon of hope for the entire world.
"Ensuring there remains no physical border between the Irish Republic and Northern Ireland is absolutely necessary for upholding this landmark agreement, which has transformed Northern Ireland.
"It is deeply concerning that the United Kingdom is now seeking to unilaterally discard the Northern Ireland Protocol.
"Negotiated agreements like the protocol preserve the important progress and stability forged by the Good Friday Accords, which continue to enjoy strong bipartisan and bicameral support in the United States Congress.
"As I have stated in my conversations with the Prime Minister, the Foreign Secretary and Members of the House of Commons, if the United Kingdom chooses to undermine the Good Friday Accords, the Congress cannot and will not support a bilateral free trade agreement with the United Kingdom.
"Respectful of the will of the British people and of Brexit, I urge constructive, collaborative and good-faith negotiations to implement an agreement that upholds peace.
"The children of Northern Ireland, who have never known the bloody conflict and do not want to go back, deserve a future free of the violence where all may reach their fulfilment."
The comments from Ms Pelosi are a reminder of the ongoing interest in Northern Ireland at the highest levels in Washington, amid political instability following the Assembly election.
The DUP is currently blocking the re-establishment of Stormont's power-sharing institutions in protest at the protocol.
This week, British Foreign Secretary Liz Truss announced plans to legislate to override parts of the Brexit withdrawal treaty the UK struck with the EU.