Enda Kenny has insisted Ireland’s Brexit negotiating position will not be undermined by his looming departure as leader in the coming weeks.

And the Taoiseach said any Brexit deal should include language that would allow Northern Ireland to easily return to the EU in the event of an united Ireland.

Mr Kenny said the provisions that allowed East Germany to join West Germany and the EU “in a seamless fashion” after the fall of the Berlin wall offered a precedent.

He said that “in such future time, whenever that might be, were it (reunification) to occur, that the north of Ireland would have ease of access to join as a member of the European Union again . . . we want that language inserted into the negotiated treaty, the negotiated outcome, whenever that might occur.”

After a meeting in Brussels, European Commission president Jean Claude Juncker said his “best relations possible” with Dublin would continue regardless of what the future holds.

“Our focus is on the discussions up ahead and that is our only focus,” said Mr Kenny at a joint press conference in Brussels. “I am focused entirely on the political issues here.”

A day after promising a “conclusive” decision on the leadership question after St Patrick’s Day, Mr Kenny said he would like to represent Ireland at the EU’s 60th summit next month in Rome, and at the EU summit handing the commission its Brexit negotiating mandate after London triggers the Article 50 process to leave the union.

“I do hope to be in attendance . . . and play our part in setting out our priorities,” said Mr Kenny.

President Juncker said he was anxious to “minimise the impact” of Brexit on Ireland and “put certainty where there is now uncertainty” with regard to complex Irish challenges which he insisted were “European challenges”.

To achieve this end, Mr Junker vowed to work “as closely as possible with Enda” in the coming weeks and months. “If something would happen that would lead me to be very sad, the relations between persons are not linked to function,” said Mr Juncker.

Both men expressed their opposition to a hard border between the Republic and Northern Ireland and confidence that any final Brexit agreement would mirror language in the Good Friday agreement, leaving the legal option of Northern Ireland joining the EU in the case of a united Ireland. “The Good Friday agreement is like a poem, it speaks for itself,” said Mr Juncker.

Mr Kenny enjoys a close relationship with the European Commission president and former Luxembourg prime minister, both as Fine Gael leader since 2002 and taoiseach since 2011.

Brussels officials say there is deep awareness and understanding in EU institutions of Ireland’s particular Brexit predicament over Northern Ireland concerns, and Dublin’s particular interest in a smooth transition to a close post-EU trade relationship with Britain.

Mr Kenny’s speech last week, stressing the need to strengthen European values in this time of change, went down particularly well in the EU capital. Dublin views Mr Juncker and Commissioner Michel Barnier, EU chief Brexit negotiator who joined Thursday’s meeting, as valuable allies in underlining and amplifying the nuances of Ireland’s political situation in Brexit, particularly with the EU’s farther-flung EU capitals.

On the future of the EU, Mr Kenny and Mr Juncker are on the same page, seeing a need to move ahead to complete EU projects already on the table, in particular completing the single market, in a bid to boost the EU’s relevance for citizens.

The Irish leader and the commission president are equally cool on proposals emanating from Poland and elsewhere to respond to the Brexit vote by repatriating EU competences to national capitals. “Treaty change in the current circumstances is not the way to go, we have to make the current EU better,” said one senior EU official on Thursday.

Earlier at a lunch meeting with Belgian and Irish business leaders, Mr Kenny said he was looking forward to next month’s St Patrick’s Day reception in the White House, his first meeting with US president Donald Trump.

“I want to be able to say to the president directly that I represent a small country of the EU that has been transformed by its benefits,” he said. A reflective Mr Kenny told his lunchtime audience of his most memorable visits to Belgium as taoiseach among the blur of Brussels summits.

Ceremonies marking the centenary of the first World War had stayed with him, and he had a “powerful memory” of hearing a children’s choir sing, Stille Nacht (Silent Night) at the site of the famous Christmas Truce of 1914.

A century on, the rise of European populists and extremists were a timely warning to today’s leaders to heed voters’ concerns. “We are in a fragile Europe, ” he said.

Earlier Mr Kenny held bilateral talks with Belgian prime minister Charles Michel, a meeting dominated by looming Brexit negotiations. As two small countries with bilateral trade ties worth €13 billion annually and a similar pro-business outlook, Belgium shares Ireland’s concerns for as smooth a departure as possible for Britain from the EU, and for its post-EU relations with the bloc.

At the lunchtime meeting With Mr Kenny, Belgian managers confirmed their shared concerns as their Irish counterparts over maintaining close trade ties with Britain.

“There are risks but we emphasise the opportunities too, particularly for Irish companies in Brussels,” said Mr Guy Ooms of Sigmund, a change communication office based in the Belgian capital. “There are so associations here all needing services: IT, communications, marketing.”