Taoiseach Micheál Martin will attend the British-Irish Council in Wales, along with British Prime Minister Keir Starmer.
The gathering will focus on supporting the creative sectors across the UK and Ireland.
Tánaiste Simon Harris and Minister for Foreign Affairs Helen McEntee will also be in attendance today.
The British-Irish Council is an intergovernmental forum, set up as part of the Good Friday Agreement to promote good relations.
It is understood that the Taoiseach will have a bilateral meeting with Mr Starmer on the sidelines of the summit.
The summit will be hosted by Welsh First Minister Eluned Morgan, with leaders of the devolved administrations in Scotland, Northern Ireland and the governments of the Isle of Man, Jersey and Guernsey also due to attend.
While unlocking the potential of creative industries is the theme of the meeting, leaders will also discuss wider political developments, including international issues.
It comes at a time when both the Irish and UK governments seek to improve relations and also work on implementing a joint framework to deal with the legacy of the troubles in Northern Ireland.
Speaking ahead of the summit, the Taoiseach described the British-Irish Council as "a welcome opportunity to build relationships and cooperation and to share learnings with our nearest neighbours".
He added that "having positive relations across these islands matters to us all, and this summit is an opportunity to underline the importance of the Good Friday Institutions to maintaining that totality of relationships".
The Tánaiste is expected to meet with Scottish First Minister John Swinney and Chief Secretary to the UK Prime Minister Darren Jones on the margins of the British-Irish summit.
He is expected to tell the forum that, as Minister for Finance, he looks forward to advancing the Irish-British trading relationship which is worth approximately €2.4 billion per week.
Speaking ahead of the summit, Mr Harris said that "in these uncertain times it has never been more important for us to closely cooperate with our nearest neighbours".
"We have made real progress when it comes to the British-Irish relationship over the last 18 months and we are committed to furthering these links in order to achieve tangible benefits for all our people," he added.
