The government and the EU have vowed to work intensively to quell tensions over post-Brexit checks at Northern Ireland ports. In a joint statement, both sides said talks on Wednesday with Northern Ireland leaders were constructive.
The talks were arranged after checks at some ports were suspended following sinister threats made to staff.
UK and EU leaders say they condemn unreservedly any threats or intimidation.
Virtual talks between the Cabinet Office Minister Michael Gove, his EU counterpart, Vice-President Maros Šefčovič and Northern Ireland's leaders were held on Wednesday amid an escalating row over applying new trade rules for Northern Ireland.
The dispute has arisen because, under the Brexit agreement with the EU, some products entering Northern Ireland from Great Britain must be checked on entry. That is because unlike the rest of the UK, Northern Ireland has remained in the single market for goods.
As a result, some food supplies and online shopping deliveries from Great Britain to Northern Ireland have been subject to delays and staff carrying out inspections have reported threats.
Tensions were also heightened when the EU threatened emergency controls of Covid vaccine exports on the Irish border - a move the bloc later withdrew.
In a joint statement, Mr Gove and Mr Šefčovič said they would work intensively to find solutions to outstanding issues.
The UK government and EU Commission reiterated their full commitment to the Good Friday Agreement, and to the proper implementation of the Northern Ireland protocol.
Both leaders said they condemned unreservedly any threats or intimidation, and stressed that the safety and welfare of the people of Northern Ireland would always be the utmost priority.
The BBC's political editor, Laura Kuenssberg, says sources told her there wasn't much progress but both sides have agreed to keep talking.
The source added that the EU wasn't in sackcloth and ashes after it temporarily suspended agreements made as part of the Brexit deal last Friday.
The UK government has called for temporary lighter enforcement of the rules to be extended until early 2023.
Northern Ireland's First Minister and DUP leader Arlene Foster warned that simply extending grace periods for businesses would not solve the problem.
She said the Northern Ireland Protocol - the arrangements for the Irish border - cannot work and must be replaced.
Deputy First Minister Michelle O'Neill, from Sinn Fein, called for calm heads and welcomed Mr Šefčovič's intended visit to the UK next week for further talks, saying it was a very pragmatic and very constructive way to move forward.