Prime Minister Boris Johnson has started a series of meetings with political leaders on a visit to Northern Ireland.
He is meeting with the region's First Minister Arlene Foster and Deputy First Minister Michelle O'Neill at Hillsborough Castle, as well as his first face-to-face meeting with Taoiseach Micheal Martin.
This is also Mr Johnson's first visit to Northern Ireland since the coronavirus pandemic struck.
He is expected to outline the first stage of plans to mark the centenary of Northern Ireland's foundation.
Discussions are also expected to take place around the response to Covid-19, rebuilding the economy and Brexit.
Arriving at Hillsborough Castle in county Down earlier, Mr Johnson was greeted by Northern Ireland Secretary Brandon Lewis before exchanging pleasantries with the First and Deputy First Ministers on the veranda in the gardens.
Ms O'Neill inquired after his baby son Wilfred, to which Mr Johnson responded that he is "starting to verbalise and make noises".
Asked by Mr Lewis how he was sleeping, Mr Johnson replied it was "not an issue", adding that the baby "goes out like a light".
Northern Ireland was created in May 1921 following the partition of Ireland.
A forum and historical advisory panel will work alongside the Government to commemorate the anniversary.
Speaking ahead of his visit, the Prime Minister said: "As we mark 100 years since the creation of Northern Ireland, it is important that we celebrate its people, culture and traditions, along with its vital contribution to the United Kingdom."
Mr Johnson said the pandemic had demonstrated the strength of the UK and that Westminster and Stormont have worked closely together to get through the crisis.
He promised these close ties will continue.
"As the country begins to get back on its feet in the wake of coronavirus, we cannot simply strive to rebuild, but we must commit to building back stronger than ever.
"I cannot overstate how important the close co-operation that we have seen between central and devolved government will continue to be to this.
The Northern Ireland Executive will receive £2.2 billion additional funding this year for its Covid-19 response.
The Treasury has also protected more than 316,000 jobs and granted thousands of business loans.
Mr Lewis said the centenary year would promote the region on a world stage.
"I am delighted that the Prime Minister is in Northern Ireland today, and has announced the first stage of our plans to mark this centenary," he said.
"This is a fantastic opportunity for people right across the UK to celebrate Northern Ireland and its integral place within our Union.
"We will use the centenary next year to promote it on the world stage, celebrating its people, culture, traditions and enterprise and its vital contribution to the United Kingdom."
The Prime Minister then met with Taoiseach Micheal Martin for the first time since the Fianna Fail leader was elected to the position in June.
The men greeted each other with an elbow bump outside Hillsborough Castle.
"I had the honour of meeting the Taoiseach several year ago," Boris Johnson said.
"I am very pleased to develop our friendship and relationship now."
He added: "It's great to see you Taoiseach, it's great to be here in Northern Ireland and we look forward to developing our relationship in all sorts of ways - east-west, north-south, you name it."
Mr Martin said the relationship between him and Boris Johnson would work "very warmly".
"We look forward to a very warm engagement," he said.
"It is important for us both in terms of the British-Irish relationship which has been the cornerstone of much progress on the island of Ireland and between our two countries for well over two to three decades, and we want to maintain that.
"It is challenging times ahead with Covid, Brexit, all of that."
Mr Martin said it was particularly fitting the engagement was taking place so soon after the death of former SDLP leader John Hume.
"We remember John at moments like this because he did so much to facilitate these kind of meetings and make them much more regular in the normal course of events," he said.
Mr Johnson agreed that the meeting provided an appropriate moment to remember Mr Hume's legacy.
The Prime Minister promised to develop Britain's relationship with Ireland after meeting the new Taoiseach.
Shortly after arriving at the castle, the Taoiseach joined the Prime Minister for a walk in the grounds.
Our reporter Vicki Hawthorne has been following today's events: