US Speaker of the House Nancy Pelosi has again warned the UK government that there will be no trade deal between the United States and the UK if Brexit threatens the Good Friday Agreement.
Ms Pelosi was asked about the latest Brexit developments at her weekly press conference on Capitol Hill.
She recalled a previous visit to the UK and said that at the time she had communicated to all sides: "Don't mess with the Good Friday accords!"
Ms Pelosi then made reference to hearing the news this week that the UK had sought to revisit its Brexit deal.
"What were they thinking? Whatever it is, I hope they are not thinking of a US-UK bilateral trade agreement.
"They won't get a reward if they undermine the Good Friday Agreement."
Ms Pelosi said her message to the UK government was very simple and something she has said in the past.
"There will be no bilateral US-UK agreement if the Good Friday accords regarding the border are changed," she said.
"How can they walk away from an international agreement, how do you trust that?
"Their self-determination is up to them, our trade relations are up to us."