Just the mention of chlorinated chicken was enough to trigger a brief flash of temper from an otherwise amiable Ted McKinney.
The US Deputy Agriculture Secretary had earlier extolled the advantages of two way trade across the Atlantic when he spoke at The Oxford Farming Conference.
But when asked how he squared this with differing standards, for example on chlorine washing of chicken carcases, he flared up.
“We will put up our standards with any one else’s any day of the week.
"I am sick and tired of hearing about chlorinated chicken. We do not do that. I will not take any more questions on that. Move on."
Defra Secretary State Michael Gove tried to calm the situation by saying negotiations should not concentrate on barriers to trade first but look for common ground as a starting point.
But Mr McKinney’s outburst may be sign of how the Trump administration handles criticism.
Defra Secretary Michael Gove said, last year, a US push for chlorinated chicken to enter the UK would stop a trade deal dead in its tracks.
He made the promise during an exchange with the Environment, Food and Rural Affairs Select Committee this week.
New Ipswich MP Sandy Martin grilled the minister on whether standards would be diluted in order to secure a post-Brexit trade deal with the USA.
“One of the things the cabinet has agreed, and we had this discussion, is we cannot compromise high environmental or high animal welfare standards in the pursuit of a trade deal”, Mr Gove said.