The Brexit minister on Tuesday admitted relations with Brussels could be "a little bumpy" for some time, but questioned the EU's response over issues such as the Northern Ireland protocol.
Lord David Frost told a Westminster committee that talks with the EU over how to implement the Northern Ireland Protocol had progressed in “one or two areas”, but that time was running out.
He said: "I think the EU does need to try and find a way of dealing with big third countries in its neighbourhood that is a bit more responsive, and sort of fleet-of-foot rather than a cookie-cutter approach and fitting everything into a template.
"If I had one criticism, perhaps it is that sometimes it feels like the resort to threats is a bit quick and you know, we don't make threats in quite the same way as I think some players in the EU do, and I think if we could just sort of dial that down a bit it would help.
"There's been a big change in the relationship, and lots of things have changed very rapidly and everybody is kind of adjusting to that.
"I think it's reasonable to think it will be a little bumpy for some time being because of that.”
Lord Frost also admitted the protocol was "not satisfactory" and suggested it was "hard to see how it can be sustained" in its current form.
Northern Ireland still follows the EU’s customs union and single market rules, unlike the rest of the UK, to avoid a hard border.
Lord Frost continued: “If those arrangements are going to be sustainable, they have to operate in a pragmatic and proportionate way – and that’s not what’s happening.
"The delicate balance in the Good Friday Agreement risks being unsettled.
"We are implementing the protocol as best we can and spending a lot of money on it, but there are still still big problems, and this is creating a sense of difficulty for identity in Northern Ireland."
One of the key issues is the ongoing sausage war over the EU’s ban of chilled meats crossing from Great Britain to Northern Ireland that is due to begin at the end of this month.