“Put very simply, we cannot go on as we are,” he said Wednesday in Parliament’s upper chamber, the House of Lords.
Frost said “the circumstances exist to justify the use of Article 16,” an emergency brake in the agreement allowing for it to be suspended by one side in extreme circumstances.
“Nevertheless, we have concluded that this is not the right moment to do so,” he said.
The EU says Prime Minister Boris Johnson’s government knew full well that there would be checks when it signed the Brexit deal.
“Britain decided itself to leave the single market of the European Union, to apply trade rules, to apply red tape to its goods that are leaving Britain, to goods that are coming into Britain,” Irish European affairs minister Thomas Byrne said.
Frost said Britain was seeking a “standstill period” in which grace periods that are due to expire in the next few months would be maintained.
Last month, the two sides gave themselves breathing time by delaying until the end of September a ban on chilled meats such as sausages from England, Scotland and Wales from going to Northern Ireland.
The “sausage war” has been the highest-profile element of the U.K.-EU dispute, raising fears that Northern Ireland supermarkets may not be able to sell British sausages, a breakfast staple.