Prime Minister Rishi Sunak is to pledge to "give everything" to help fulfil the promises of the Good Friday Agreement.
Mr Sunak will deliver a closing speech at a Queen's University Belfast conference marking the 25th anniversary of the historic peace deal.
The Prime Minister will later host an evening gala dinner to commemorate the 1998 agreement, which largely ended Northern Ireland's three-decade sectarian conflict known as the Troubles.
Read more: Get on and do the right thing, former PM tells Stormont leaders at Good Friday Agreement conference
Taoiseach Leo Varadkar is also set to give a keynote speech on the last day of the Agreement 25 conference.
Mr Sunak will say the best way to honour the Good Friday Agreement is to create jobs and opportunities for young people so they can fulfil their aspirations at home.
The Prime Minister is expected to say "we have work to do" to deliver on the promise of a more prosperous and integrated society.
"Together we must fulfil the true promise of the 1998 Agreement," he will say.
"That future enshrined in the very words of the text - of 'sustained economic growth', and where we tackle the problems of 'a divided society'.
"And I will give everything to help deliver that vision."
He will add: "I know that journey to prosperity won't be easy – and we aren't there yet.
"But this is my commitment to you: I will use the full force of the UK Government to help you make this one of the best places in the world to start and grow a business, create jobs, train and learn new skills, and attract investment."
Mr Sunak will also pay tribute to the "courage, imagination and perseverance" of the political leaders who brokered the Good Friday Agreement.
He is expected to praise police and security services in Northern Ireland for their work in the face of threats to them and their families.
The Prime Minister's return to Belfast follows his visit last week welcoming US president Joe Biden as he arrived for a four-day trip to the island of Ireland.
During an address in Dublin, Mr Biden said the UK "should be working closer" with the Irish government to support Northern Ireland.
Both the US and UK dismissed speculation of tensions over the planning of the president's trip after Mr Sunak greeted Mr Biden but did not attend a keynote speech he gave in Belfast.
Mr Sunak will meet with some of those involved in the Good Friday Agreement at an evening gala dinner.
It will also be attended by political leaders, Irish government and US representatives, international dignitaries and leading charities.
The anniversary of the Good Friday Agreement comes at a time when Stormont's power-sharing institutions established from the agreement have collapsed, as the DUP is blocking them in protest against Brexit's Northern Ireland Protocol.
The UK and European recently agreed the Windsor Framework in a bid to reduce barriers to trade between Great Britain and Northern Ireland created under the protocol.
While the DUP says the framework has gone some way to address its concerns about the protocol, it says significant issues remain.
Addressing the Agreement 25 conference at Queen's on Tuesday, the Northern Ireland secretary urged unionists to "put the Union first" and restore the devolved institutions.
Chris Heaton-Harris said "real leadership" was about having the courage to say "yes" as he hailed decisions made by previous unionist leaders during the peace process.
But DUP leader Sir Jeffrey Donaldson said they would not be "brow beaten" into a return to power-sharing.
He tweeted: "The great and the good can lecture us all they want for a cheap round of applause but it won’t change the political reality.
"The political institutions only work when there is cross-community consensus. Berating unionists won't solve the problem. They didn't do it to Sinn Fein (when the party collapsed power-sharing in 2017) and we will not be treated differently or brow beaten into submission.
"The government need to work with us to address concerns and get the outstanding issues resolved. We stand ready to get the job done and see Stormont restored. But it has to have a solid foundation."
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