Gordon Lyons has accused US congressman Richard Neal of having a “one-sided view of Northern Ireland.
The DUP Stormont Economy Minister said the congressman “clearly takes a different view than unionists would”.
Mr Lyons added: “He has worked closely together with Friends Of Sinn Fein in America, attending their events.
“He has planted trees in memory of hunger strikers and spoken glowingly about them. He commended president (Michael D) Higgins for not attending a service to commemorate the centenary of Northern Ireland.
“He has said he is hopeful there will be a united Ireland in his lifetime.
“So, yet again we are dealing with more American politicians who are very much one-sided.
“That adds to the challenge, but we are up for that, and letting them know about the issues that the protocol is causing.”