The European Union's chief interlocutor on the Northern Ireland Protocol Maroš Šefčovič has told member states he will bring forward a range of proposals by the end of September or early October in order to try to resolve the ongoing deadlock around the Protocol.

Mr Šefčovič held talks with Taoiseach Micheál Martin at Government Buildings today.

Earlier, he said he hopes an overall deal can be reached with the UK by the end of the year, although he cautioned that success was not guaranteed.

He told EU ambassadors at a meeting in Brussels that the proposals would cover the issues of customs, agrifood, medicines and ways to strengthen the role of the Northern Ireland institutions in overseeing the implementation of the Protocol.

Meanwhile, a senior EU official has expressed concern that the UK is increasingly raising the sovereignty issue when outlining its objections to the Protocol.

In particular, the official said the UK is raising fresh complaints, such as the role of the European Court of Justice (ECJ) in overseeing the Protocol, that had not been expressed to the EU a number of months ago.

The official said the issue of medicines was also now being linked to the sovereignty question, since the EU’s proposed solution to the medicines question would involve the UK applying EU regulatory procedures in Great Britain in order to ensure the free flow of medicines from there into Northern Ireland.

The official said the sovereignty question was "starkly" set out in the speech last weekend at the British Irish Association by Lord Frost, Mr Šefčovič's opposite number on the UK side.

It was also implicit in the UK’s so-called Command Paper on the Protocol, published on 21 July.

The official said a new UK fixation on sovereignty would hamper the quest for practical solutions on the ground that could ease the implementation of the Protocol.

Following his working dinner in Government Buildings tonight, Mr Šefčovič will travel to Northern Ireland tomorrow morning for a series of meetings with businesses, stakeholders, civil society and political leaders.

Officials say the object of the visit is to ensure that businesses, stakeholders and politicians can clearly outline what their concerns around the Protocol are, and that the EU can in turn explore practical solutions.

However, officials also say that Mr Šefčovič will be "managing expectations" around the way forward.

"This is pretty important in light of the Command Paper," said the EU official.

"We think certain stakeholders in Northern Ireland need to hear that the Protocol will not be rewritten. We will find solutions in its implementation, but we will not propose to the UK to start renegotiating. Because we don't think there is an alternative."

Member states are said to have supported Mr Šefčovič during today's meeting with ambassadors in his bid to break the deadlock with new proposals.

However, a number of ambassadors said the EU would need to prepare a response if the talks process with the UK in the next months did not bear fruit.