Britain has defended its extension of grace periods to allow businesses to adapt to new regulations under Brexit after Brussels said London had violated its obligations by doing so unilaterally.

On Wednesday, a Brussels official said Britain had unilaterally extended the transition phase of a key protocol for food deliveries to Northern Ireland until October without consulting the European Union (EU).

The European Commission said Britain’s decision to continue grace periods regarding checks along the Irish Sea border until October is a violation of its post-Brexit obligations.

Britain’s former Brexit negotiator David Frost spoke to European Commission Vice President Maros Sefcovic and explained that the changes were to help businesses cope, a British government spokesman said Wednesday evening.

The measures followed official-level notification to the EU earlier this week, the statement said.

Frost called the measures “temporary technical steps, which largely continued measures already in place, to provide more time for businesses such as supermarkets and parcel operators to adapt to and implement the new requirements.”

During the call, he said those were needed “for operational reasons and were the minimum necessary steps” to allow time for constructive discussions to continue without the prospect of disruption to the everyday life of people in Northern Ireland in the coming weeks.

Both agreed that both parties would remain in close contact.

Border checks were put in place between Northern Ireland and mainland Britain after it left the European Union’s single market on December 31 to monitor goods entering and leaving the bloc.

The arrangement was made to keep the politically sensitive border open between Northern Ireland and the Republic of Ireland, which remains an EU member. Still, goods checks have already led to delays and attacks against officials.

Businesses in Northern Ireland had been calling for an extension to the grace periods to avoid the sudden increase in bureaucracy linked to the protocol.

Mr. Sefkovic had earlier said that Britain is set to breach international law for a second time by delaying some goods’ grace periods.

The Irish government also called the extension “deeply unhelpful,” the PA news agency reported.

Mr. Sefkovic said in a statement that he had expressed the EU’s “strong concerns over the UK’s unilateral action, as this amounts to a violation of the relevant substantive provisions of the protocol on Ireland/Northern Ireland and the good faith obligation under the Withdrawal Agreement.”

He called it a departure from the constructive approach that has prevailed up until now, saying the move undermined the work and trust needed for solution-oriented co-operation.