On April 10, 1998 -- Easter Good Friday -- pro-Irish nationalist and pro-UK unionist leaders struck an unlikely peace deal following marathon negotiations involving governments in London, Dublin and Washington.

But as the province approaches the milestone of a quarter century of peace, the mood is one of pragmatic reflection rather than celebration.

"The great hopes of '98 definitely have not been met," Duncan Morrow, professor of politics and conflict resolution at Belfast's Ulster University, told AFP.

"On the other hand, very few people are suggesting that life before the agreement was better than after."

Power-sharing institutions created by the peace accords have been left paralysed for more than a year over bitter disagreements on post-Brexit trade that show no sign of abating.

And in the wake of an assassination attempt on a police officer by dissident republicans in February, Northern Ireland's terror threat level was this week raised to "severe".

Over the coming weeks, Belfast is due to host a series of events with serving and former international heads of state and government to mark the formal end of the conflict which claimed the lives of 3,500 people.

- 'Always a process' -

In March, US President Joe Biden accepted an invitation from British Prime Minister Rishi Sunak to take part in events for the anniversary.

The US leader is expected to visit both Northern Ireland and the Republic of Ireland during his trip.

From April 17, Queen's University Belfast will hold a three-day conference hosted by former US secretary of state Hillary Clinton, whose husband, Bill Clinton, played a pivotal role in securing the peace deal as US president from 1993 to 2001.

Events will focus on the transformation in Northern Ireland over the last quarter century.

In the years after the agreement was signed, Northern Ireland's paramilitaries were disarmed, its militarised border dismantled and British troops departed.

In an interview with AFP ahead of the latest anniversary, former Irish prime minister Bertie Ahern, who was instrumental in negotiating the accords, contrasted the recent period of peace with what had come before.

"It was always a process, and the last 25 years have been so much more pleasant and so much more comforting than the previous 25 or maybe the previous 75," Ahern said.

But the peace in Northern Ireland is perhaps more precarious in 2023 than it has been at any other point since the 1998 signing of the Good Friday Agreement.

- Brexit woes -

The pro-UK Democratic Unionist Party (DUP) has boycotted Northern Ireland's devolved government for more than 13 months in opposition to post-Brexit trading rules there, crippling the assembly and its executive.

Sporadic violence has erupted in unionist communities in the years since the UK's departure from the European Union, over the so-called Northern Ireland Protocol.

They fear that it pulls the province away from the UK and makes a united Ireland -- the goal of pro-Irish nationalists -- more likely.

In an intervention earlier this month, former British prime minister Tony Blair, who also contributed to reaching the deal, said Brexit was "a difficult circle to square" when it came to Northern Ireland and urged progress restoring power-sharing.

A renegotiation of parts of the protocol by the EU and UK -- labelled the Windsor Framework -- largely aimed at remedying unionist concerns has so far been spurned by the DUP.

In January, polling for The Belfast Telegraph newspaper found a majority of unionists would vote against the Good Friday Agreement in a contemporary re-run of the 1998 referendum that ratified the deal.

Last month's attempted murder of police officer John Caldwell, who was shot multiple times as he left a sports complex with his son, united Northern Ireland's political leaders in condemnation.

But the attack in Omagh, claimed by republican dissidents, has served as a stark reminder of the kind of violence that was once commonplace across the province.