Brexit is expected to dominate the agenda as leaders from across the UK and Ireland attend a meeting on the Isle of Man on Friday.
Taoiseach Leo Varadkar; the UK's de facto deputy prime minister David Lidington; Scottish first minister Nicola Sturgeon; and first minister of Wales Carwyn Jones will be among those attending the British Irish Council (BIC) summit.
Representatives of the governments of Guernsey, Jersey and the Isle of Man will also participate in the 31st summit meeting of a forum set up as part of Northern Ireland's Good Friday peace agreement.
Northern Ireland ministers have been absent from the twice-yearly gatherings in recent years due to the powersharing crisis at Stormont. Northern Ireland Secretary Karen Bradley will attend the event.
The BIC summit is the last before Brexit and comes amid ongoing deadlock over the thorny issue of the Irish border.
The UK and EU’s failure to agree a backstop position – to maintain a free-flowing border even if a wider trade deal fails to materialise – continues to stand in the way of an agreed exit deal.
The devolution impasse in Belfast is also set to feature in the political discussions on Friday, with the UK and Irish governments having yet to agree a strategy on how to re-initiate talks between the region's rowing politicians.
UK prime ministers have attended BIC meetings in the past, but not on a regular basis and not in recent years.
At summit meetings in the last two years, Theresa May has been criticised for not attending, given the challenges to the participating governments presented by Brexit. – PA