BELFAST - U.S. President Joe Biden will meet British Prime Minister Rishi Sunak and Northern Irish political leaders in Belfast on Wednesday, kicking off a three-day Irish tour with a speech to mark the 25th anniversary of Northern Ireland's 1998 peace deal.

Biden, who is fiercely proud of his Irish heritage, will spend just over half a day in the UK region before travelling south to the Republic of Ireland for two-and-a-half days of speeches and meetings with officials and distant relatives.

Speaking to reporters before leaving Washington, Biden said his priority was to help "keep the peace" as Northern Ireland marks the anniversary of the 1998 Good Friday Agreement that largely ended 30 years of bloodshed between mainly Catholic opponents and mainly Protestant supporters of British rule.

He also said he would seek to make sure the recent Windsor Framework deal between the European Union and Britain to ease post-Brexit trade barriers between Northern Ireland and the rest of the UK remains in place.

That deal has so far failed to convince the region's largest pro-British party, the Democratic Unionist Party (DUP), to end a boycott of the devolved power-sharing government, a key part of the 1998 peace deal.

The DUP has said Biden's visit - the first to the region by a U.S. president in 10 years - will not pressure it to end its more than year-long protest at the trade rules that treat the province differently to the rest of the UK.

While Biden is expected to greet representatives of the DUP and the other four main Northern Ireland political parties, it is unclear if they will hold separate meetings.

Biden, flanked by new U.S. special envoy to Northern Ireland for economic affairs Joseph Kennedy III on his arrival, will also float the possibility of closer U.S./Northern Ireland investment ties to try to encourage an end to the impasse.

After his speech at the Ulster University and a meeting with Sunak, Biden will travel to County Louth - midway between Belfast and Dublin - where his great-grandfather was born. Stormy weather is expected across the island on Wednesday.

Biden will meet relatives from another side of his family in the western county of Mayo on Friday.

Biden's great-great-grandfather Owen Finnegan, a shoemaker from County Louth, immigrated to the United States in 1849. His family, including Biden's great-grandfather James Finnegan, followed him in 1850.

(Writing by Padraic Halpin Additional reporting by Conor Humphries Editing by Peter Graff)