US president Joe Biden has said he will use his visit to Ireland to “keep the peace”, as he left the US for his four-day trip.
Mr Biden invoked the importance of the Good Friday Agreement and the recently negotiated Windsor Framework as he prepared to set off for the North.
Mr Biden will arrive later on Tuesday as he begins a visit marking the 25th anniversary of the Good Friday Agreement.
Mr Biden will travel to the Republic on Wednesday, where he will carry out a number of engagements during his four-day stay, including visiting Louth and Mayo – from where his ancestors hail.
His son Hunter Biden and sister Valerie Biden Owen are believed to be accompanying him for the trip.
Speaking to reporters before his departure, Mr Biden said his top priority was to “make sure the Irish accords and the Windsor Agreement stay in place, keep the peace”.
“That’s the main thing,” he said.
British prime minister Rishi Sunak will meet Mr Biden when Air Force One touches down in Northern Ireland on Tuesday evening.
The two leaders will hold a meeting on Wednesday before Mr Biden gives an address at Ulster University’s new £350 million Belfast campus.
It is expected that Mr Biden will also hold a meeting with the North’s main political parties before his talk at Ulster University.
The visit comes as the Stormont Assembly is not currently operating due to a protest over post-Brexit trading arrangements by the DUP.
A major security operation will be in place for Mr Biden’s visit, with more than 300 officers from Britain being drafted into Northern Ireland.
The PSNI has also warned of significant traffic disruption in Belfast during the presidential visit, with a number of roads in the city centre already closed.
After he leaves Belfast on Wednesday, Mr Biden will cross the Border to attend engagements in Co Louth.
The US president has traced his ancestral roots to the area, and will tour Carlingford Castle before spending the night in Dublin.
He is then expected to visit President Michael D Higgins on Thursday.
It has been announced that Phoenix Park will be closed for 24 hours from 5pm on Wednesday to facilitate the visit.
The White House said Mr Biden will take part in a tree-planting ceremony and ringing of the Peace Bell at Áras an Uachtaráin.
Following that ceremony, he will meet Taoiseach Leo Varadkar, whom the US president hosted for St Patrick’s Day.
Mr Biden will address the Oireachtas and attend a banquet dinner at Dublin Castle on Thursday evening.
His trip will conclude with a visit to Co Mayo, where he has also connected with distant cousins, on Friday.
He will tour the Sanctuary of Our Lady of Knock and visit the North Mayo Heritage and Genealogical Centre’s family history research unit.
He will then make a public speech at St Muredach’s Cathedral in Ballina.
