European Council President Donald Tusk has again insisted that Ireland must come first in the EU-UK negotiations over Brexit.
In strident comments on the matter, Mr Tusk said: "If in London someone assumes that the negotiations will deal with other issues first, before moving to the Irish issue, my response would be: Ireland first."
He was in Dublin meeting with Taoiseach Leo Varadkar ahead of a crucial EU summit in Brussels on March 22.
He spoke about the failure so far by the UK to come up with a plan to avoid a hard Border in Ireland, or create a "solution" to Brexit. Mr Tusk said the lack of a solid outline of the future EU-UK relationship, incorporating the Irish Border, was hampering progress thus far.
"As long as the UK doesn't present such a solution, it is very difficult to imagine substantive progress in Brexit negotiations", said Mr Tusk following the meeting.
He also said that while the EU respects the result of the Brexit referendum, the same should be said for the British in respecting the Irish vote for the Good Friday Agreement.
"We must recognise the democratic decision taken by Britain to leave the EU in 2016, just as we must recognise the democratic decision made on the island of Ireland in 1998 with all its consequences," said the former Polish prime minister.
"The risk of destabilising the fragile peace process must be avoided at all costs. So we will be firm on this."
Meanwhile, the Taoiseach called for "certainty" from London regarding how it plans to protect the Border and how it sees its future relationship with Brussels.
The EU issued draft guidelines for the negotiations on the future relationship earlier in the week - to be agreed by the 27 heads of state and government.
This coincided with a major speech by British chancellor Philip Hammond, who called for the inclusion of financial services as part of a future trade deal with Brussels.
"It's hard to see how any deal that did not include financial services can look like a fair and balanced deal", said Mr Hammond. He said it would be in the interests of both the EU and UK for this to happen.
However, Mr Tusk shot him down while in Dublin, saying "We cannot offer the same in services as we can offer in goods".
"In the Free Trade Agreement, we can offer trade in goods", but "services are about common rules, common supervision, and common enforcement", he said.
"I also heard the chancellor's words about financial services being 'very much in the mutual interest' of the UK and EU. I fully respect the chancellor's competence in defining what's in the UK's interest. I would, however, ask to allow us to define what's in the EU's interest."