Joe Biden has landed in Northern Ireland ahead of a four-day visit to the island of Ireland to underpin his support for peace in the country and to celebrate his Irish roots. The US president was met at Belfast international airport by Rishi Sunak on Tuesday night for the start of a visit expected to mix delicate political choreography with economic announcements and events linked to Biden’s Irish and Catholic heritage. Speaking to reporters before taking off in Air Force One, Biden said he wanted to safeguard the Good Friday agreement, which was signed 25 years ago this week, and support Sunak’s post-Brexit deal for the region. Asked what his priorities for the trip were, he said: “Make sure the Irish accords and Windsor agreements stay in place. Keep the peace and that’s the main thing. It looks like we’re going to keep our fingers crossed.” The Northern Ireland secretary, Chris Heaton-Harris, and the King’s personal representative for County Antrim, Lord-Lieutenant David McCorkell, were also among the welcoming party. The two leaders met briefly before the president drove away in an armoured car amid a light scattering of snow. Heavy security on both sides of the border preceded the US entourage, which will include the US secretary of state, Antony Blinken, and a recently appointed economic envoy to Northern Ireland, Joseph Kennedy III. Dozens of police and US secret service vehicles sealed off rain-drenched streets around central Belfast on Tuesday. Manhole covers were lifted and checked and sniffer dogs inspected hotel rooms as part of a £7m security operation – bolstered by 300 extra police from the British mainland. In Derry, police recovered four suspected pipe bombs from a cemetery where republicans had staged an Easter Monday commemoration that led to petrol bomb attacks on police. The discovery was a “sinister and worrying development”, said the Police Service of Northern Ireland assistant chief constable, Bobby Singleton, with the Police Federation for Northern Ireland saying it was a clear statement of intent to cause harm to police officers. The security and logistical preparations in Belfast appeared to leave commuters and shoppers more bemused and curious than excited. “There’s enough going on here in local politics without [having] to invest time in this,” said Danielle Falkiner, who works for a Belfast manufacturer. Biden will meet Sunak again on Wednesday morning and then make a speech at Ulster University in Belfast, his only public engagement in Northern Ireland, before heading south across the border for three days of pomp and pilgrimage in Ireland. Downing Street on Tuesday was forced to deny a New York Times report that the White House had scaled back Biden’s meeting with Sunak from a bilateral event to a low-key coffee meeting. “I wouldn’t characterise it as that,” said a No 10 spokesperson. “We continue to have an incredibly positive working relationships with the president and the US government.” Sunak will not meet Northern Ireland party leaders but the spokesperson said he had not given up on persuading the Democratic Unionist party to drop its year-long boycott of power-sharing in protest against the post-Brexit Northern Ireland protocol. The mothballing of the Stormont assembly and executive has created a political vacuum and overshadowed celebrations of the Good Friday agreement anniversary. On Tuesday evening, the White House said there will not be a formal group meeting between the US president and Northern Ireland’s five main political parties. The former prime minister Tony Blair had advised the president to be cautious in using his influence to lobby the DUP to revive Stormont. “The Americans can play a real role, but it’s something that you need to do carefully.” After the university address Biden is scheduled to fly to Dublin and then travel to the border town of Carlingford in County Louth where his great-grandfather James Finnegan was born. He is to meet extended family, visit a 13th-century castle and do a walkabout in Dundalk before returning to Dublin. On Thursday, he will hold separate meetings with the Irish president, Michael D Higgins, and the taoiseach, Leo Varadkar, before making a speech to a joint sitting of parliament, following in the footsteps of John F Kennedy in 1963, Ronald Reagan in 1984 and Bill Clinton in 1995. There will be a banquet dinner at Dublin Castle. On Friday, Biden will fly to County Mayo and tour the Sanctuary of Our Lady of Knock, a Catholic shrine, where he is expected to pray. He will also visit the North Mayo Heritage Centre’s family history research unit and meet relatives from another side of his family before making a speech that evening outside St Muredach’s Cathedral in Ballina. “It’s brilliant,” said Laurita Blewitt, a fourth cousin who has met the president several times in Ireland and Washington. “Ballina is a buzz of excitement – flags, bunting, welcome signs. We’re really looking forward to Friday. “It’ll be a historic day for the town.” The only problem, besides traffic havoc caused by security, is the threat of rain, said Blewitt. On Thursday night, she said, residents will put out Child of Prague statues in keeping with a folklore belief that this increases the chances of good weather.