Brussels indicated on Monday it is willing to be flexible to ease the impact of post-Brexit trade checks on businesses in Northern Ireland, while warning that only British alignment with the bloc’s food safety rules can remove some of the irritants that have emerged.

EU Brexit commissioner Maros Sefcovic and his UK opposite number David Frost are overseeing talks on how to implement the so-called Northern Ireland protocol, after the UK’s move to unilaterally suspend some administrative demands linked to the new rules triggered legal action from Brussels.

Both sides are striving to work out how to apply the new trading system in a way that reduces tensions that helped stoke rioting in the region last month.

An EU official on Monday said the bloc had already identified solutions to some practical problems with the arrangements, which place a customs and regulatory border down the Irish Sea so as to preserve seamless trade on the island of Ireland. The steps have included facilitating travel for guide dogs and ensuring that farm animals do not have to be repeatedly retagged as they pass between Great Britain and Northern Ireland.

While the protocol has been denounced by unionist politicians in Northern Ireland, the official said Brussels still believed that ultimately it could offer the region’s businesses “the best of both worlds” by placing them inside both the EU and UK markets.

But the official also underlined that only a comprehensive veterinary agreement between the two sides could eliminate the need for some checks, and that this would require a fundamental shift in Britain’s position.

Britain has repeatedly rebuffed suggestions from Brussels that it should sign a veterinary agreement committing the whole UK to stay in sync with the bloc’s rules, saying it would run counter to the purpose of Brexit and restrict the country’s future trade policy.

Brussels officials are convinced that the reticence is linked in part to the UK’s ambitions to do a trade deal with the US, which has different regulatory standards on food, notably by allowing hormone treated beef and chemically-washed chicken.

UK officials have signalled that the government would be willing to explore an alternative model based on an agreement the EU has with New Zealand under which the two sides recognise each other’s standards as of equivalent rigour.

But Brussels has said the New Zealand agreement covers only a very limited number of products in a far smaller trading relationship. Such an agreement “would reduce the need for checks without eliminating them,” said the EU official.

One idea mooted to resolve the differences over the protocol in Brussels is that the UK could temporarily sign up to a dynamic alignment deal on veterinary standards and only pull out should that become necessary because of trade deals in the future.

“We think that if the UK remains aligned with our high standards many of the problems we face will go away,” said the EU official.

The official said there was even the potential to put such a dynamic-alignment arrangement in place during a temporary period — a “window” of perhaps several years.

This would work on the basis that the UK could end the arrangement in future, for example because it needed to implement a trade deal with different food standards, or for any other reason. In such a scenario, checks would be reintroduced, but in the meantime there could be smoother trade across the Irish Sea.

The EU official acknowledged that Britain has so far given no sign of embracing the idea. “Only a structural shift in the position of the UK can lead to a reduction in the number of checks and so forth,” said the EU official.