The EU's chief Brexit negotiator has told member states there is no sign of an imminent breakthrough in the Northern Ireland Protocol negotiations with the UK, RTÉ News understands.

Maroš Šefčovič told EU European affairs ministers in Brussels that a meeting with the UK foreign secretary Liz Truss yesterday was "difficult" and "frustrating", according to one account of his briefing this afternoon.

While Mr Šefčovič has expressed his appreciation for a friendlier atmosphere in the talks, he told EU ministers that Ms Truss had brought up new issues around the Protocol which the EU believes were dealt with during the Withdrawal Agreement and Trade and Cooperation Agreement (TCA) negotiations.

Mr Šefčovič said a meeting of the EU UK Joint Committee would take place on 21 February.

"Šefčovič said the view of both sides was that it would be excellent if that Joint Committee were in a position to take some decisions," says one source present at the briefing.

"But it's not at all clear whether that would be the case or not. It just means it would be great if that Joint Committee could record progress, and maybe actually decide one or two things. But that’s not clear."

Mr Šefčovič told ministers that Ms Truss wanted to renegotiate the Protocol and had sought changes to how state aid is handled.

It is understood London wants state aid provisions in the Northern Ireland Protocol to be handled the same way as they are in the TCA.

However, the European Commission has stressed that the Protocol provisions on state aid are linked to the fact that Northern Ireland is de facto in the Single Market, whereas the TCA state aid provisions relate to an international trade agreement.

EU ministers are said to be concerned that the political upheavals around the UK prime minister Boris Johnson in Westminster are making an agreement by the end of February very difficult.

It is understood that technical teams from both sides will now focus their attention on customs checks on goods and regulatory checks on agrifood products, with Ms Truss and Mr Šefčovič meeting in London again on Thursday of next week.

The two teams will conduct what Mr Šefčovič described as a "joint gap analysis".

The nub of these technical talks is to establish how far checks and controls on goods crossing the Irish Sea can be lowered, while giving the European Commission and member states the reassurance that unregulated goods are not leaking into the Single Market.

So far these have proved the most difficult areas of discussion, with the UK demanding no checks at all on goods that are only being delivered to Northern Ireland.

"It basically seems to mean, what does the Commission require in order to reduce checks and controls down to a very modest level, and what does the UK actually have at its disposal in order to satisfy the safeguard requirements of the EU?," says one diplomat.

Both sides are said to be keen to secure agreement before campaigning for the Northern Ireland Assembly elections gets under way in March, although they are wary of setting deadlines.

In a news conference this afternoon Mr Šefčovič said both sides should stay "laser-focused" on practical challenges raised by Northern Ireland stakeholders.

He said: "With political goodwill we can have a timely agreement on durable solutions that would immediately and significantly help operators and people on the ground. This is about ensuring stability, predictability, prosperity and peace in Northern Ireland."

"But this is also about building trust," he added.