Mick Mulvaney said the agreement could be “at risk” because of the UK Government’s controversial Internal Market Bill, but that it was something the United States was “very interested in seeing not happen”.
He made the comments on a visit to Dublin on Monday where he met with the Taoiseach Micheál Martin and Foreign Affairs Minister Simon Coveney.
His visit comes as the British government rebuffed a fresh demand from the EU to withdraw the Internal Market Bill, which could see the UK unilaterally tear up elements of the Brexit divorce deal.
Mr Mulvaney said the US was watching the EU/UK negotiations closely.
“I think it’s fair to say we are aware and cautious and watching the situation,” he said.
“Concern would imply that we’re worried and I don’t think we’re at that point yet but we certainly understand the interplay between the EU/UK trade deal and the Internal Market Bill and the Good Friday agreement.
“That’s mostly while I’m here. I have not been able to be here previously because of Covid.”
He told RTE News that the Good Friday Agreement could be “at risk”.
He said: “I don’t think it necessarily follows that just because the UK introduced the Internal Markets Bill that automatically means the Good Friday Agreement is at risk.
“But I think anyone who looks at the situation understands there could be a series of events that could put the Good Friday Agreement at risk.
“Again something we’re very interested in seeing not happen in the United States.
“We’re here to protect, defend that Good Friday Agreement that was so hard fought and won.”
Mr Mulvaney met Mr Coveney on Monday morning.
Following the meeting, Mr Coveney said the two men discussed the return of powersharing in Northern Ireland, the work that has resumed on a North-South basis and the challenges arising in the context of Covid-19 and of Brexit.
“I emphasised our real concern at the current approach of the UK Government and the vital importance of the full implementation of the Withdrawal Agreement and the Protocol on Ireland/Northern Ireland, for the protection of the Good Friday Agreement and the achievements of the peace process,” Mr Coveney said.
“Those achievements were made possible by the sustained engagement of successive US administrations and special envoys, and friends of Ireland across the United States.
“I appreciate the deep personal commitment that Mick has shown in continuing these vital conversations and contacts which underpin this engagement.”
Mr Mulvaney also met with the leader of the opposition and president of Sinn Fein Mary Lou McDonald during his visit to Dublin.
On Sunday, he met Northern Ireland Secretary Brandon Lewis in Belfast. Speaking afterwards, he said he believed the UK and the European Union could still reach a trade deal that would be acceptable to all sides.
The former acting chief of staff to US President Donald Trump took up the position of special envoy in March.
An Irish American with strong links to Co Mayo, this is his first trip to Ireland in his new role.
The diplomatic role had remained vacant since former US senator Gary Hart left the position in 2017 when Donald Trump took power.
Later in the week, Mr Mulvaney will meet representatives from Northern Ireland’s devolved government and he will also travel to London to meet with MPs.
