The UK has rejected the EU demand to set up a permanent office in Belfast, the capital of Northern Ireland.
The Republic of Ireland's national broadcaster, RTE, reported on Saturday that Helga Schmid, secretary general of the EU's external action service, told the UK in February that the EU wanted a permanent presence in Belfast in order to oversee the implantation of the Brexit deal's Irish protocol.
The protocol allows EU officials to oversee checks and controls carried out by British officials on goods moving between Great Britain (England, Wales, and Scotland) and Northern Ireland.
Schmid said the EU needed "very particular capabilities and competences on the ground, distinctive from the more traditional competences of any other EU delegation."
She wanted the new office set up by June, but Prime Minister Boris Johnson insisted there would be no new paperwork between Great Britain and Northern Ireland.
UK Paymaster General Penny Mordaunt wrote back to the EU on April 27 saying: "The UK cannot agree to the permanent EU presence based in Belfast."
Mordaunt said the EU presence would be "divisive in political and community terms."
The British government added in a statement on Saturday: "There is no reason why the commission should require a permanent presence in Belfast to monitor the implementation of the protocol."
An EU official told RTE: "The UK cannot have been taken by surprise by this. The possibility of opening an office in Belfast has been discussed for a long time at this stage. The EU has been consistent on this point."
The fear for the EU is that the UK will backtrack on commitments made under the Brexit deal agreed last year.
Britain is expected to propose an alternative to a permanent office in Belfast, but the EU is expected to stick to its position.
The UK and EU are negotiating a trade deal that must be completed by the end of the year.
