Frost accused the Biden administration of not understanding Northern Ireland.
A former Brexit minister has pushed back at the US Government over sharing their concerns about the Good Friday Agreement and the Northern Ireland Protocol.
Lord David Frost, the former Chief Negotiator for Exiting the European Union, made the comments at an event in Washington DC on Thursday night (12 May).
"I know the Administration is following this closely," Frost said in his speech as part of the "Last Exit to Freedom? Britain After Brexit and the Future of Conservative Politics" event.
"I urge them to be cautious in what they say and what they do.
"I am not convinced the niceties of Northern Ireland are well understood by this Administration and I hope they will think hard before telling a friendly government how they must act to protect the unity and territorial integrity of their own country."
Frost said that he gets frustrated whenever "a third-party - albeit a very important one in this context - how we face these issues."
"It was our country that faced terrorism, faced the Troubles.
"I'm old enough to remember checking under my car every morning as a diplomat before I went to work, and most people were very affected by this in one way or another.
"So we don't need lectures from others about the peace process and the Good Friday Agreement.
"We're well aware of this, and we don't want to go back to it."
In a statement to Belfast's daily Unionist newspaper the News Letter, DUP leader Jeffrey Donaldson said the party will
not support the appointment of a speaker as part of its campaign against the Northern Ireland protocol.
"Unionist concerns over the Northern Ireland Protocol are not merely some political squabble which is impacting upon Stormont," Donaldson said.
"The protocol is a direct challenge to the principles that have underpinned every agreement reached in Northern Ireland over the last 25 years," he added.
"The economic and political damage to Northern Ireland we see now is merely the tip of the iceberg and will only increase significantly as time moves on."
The DUP's move to block an assembly could potentially strengthen the posturing of UK Prime Minister Boris Johnson in his bid to rid the UK of the Northern Ireland Protocol, one of the remnants of Brexit.
The action means that the Assembly cannot function properly or hold debates and meetings, and Sinn Féin's Michelle O'Neill cannot take the position of First Minister.
