A BELFAST-based consultant who worked under the Clinton administration has dismissed claims that a trade deal between the UK and the US could go ahead at the expense of the Good Friday Agreement.
Francis Costello, a businessman and historian, was also chief of staff to former Democratic congressman Joseph P Kennedy II.
The Boston native, who has been living in Belfast for the past 20 years, was responding to a comment by John Deasy, the Irish government's parliamentary envoy to Washington.
Mr Deasy had warned that Ireland should not assume Democrats would vote down an American free trade agreement if the UK crashed out of the EU.
"If they want to put together a trade deal, and even if the Good Friday agreement was in jeopardy, I think it would pass in the Senate and it would be touch and go in the House (of Representatives)," Mr Deasy told the Sunday Times.
"There would be Democrats who share a view that, if the UK was to leave the EU without an agreement and if it was in the best interests of the US to do so, there would be pressure to pass a trade deal."
Two weeks ago Nancy Pelosi, speaker of the House of Representatives, whose Democratic party controls the House, said a UK-US trade deal would not get through Congress if Brexit undermined the Good Friday Agreement.
She said the UK's exit from the EU could not be allowed to endanger the 1998 Irish peace deal, which the US helped facilitate.
Dr Costello said Mr Deasy is "misreading the situation",
He said Congressman Richard Neal, chairman of the US House Committee on Ways and Means, has said it could take four years to legislate on any trade agreement.
"I have known Congressman Neal for over 30 years and as chairman he will painstakingly follow his duty to the letter.
"The border issue is not simply a trade issue. It's about social and human rights and about the peace, stability and protection of all citizens.
"There has been tremendous investment in the peace process by the US government down the years, including in terms of funding."
He added: "The Irish did not invent the border. Anything that brings us anywhere near the bad old days simply cannot be allowed go happen."
