US President Joe Biden is in Belfast on an historic four-day visit to Northern Ireland and the Republic.

Mr Biden was greeted by Prime Minister Rishi Sunak on Tuesday night as he stepped off Air Force One at Belfast International Airport.

His visit marks the 25th anniversary of the Good Friday Agreement – a peace deal which helped end 30 years of violent conflict in Northern Ireland.

The White House hailed the “tremendous progress” since it was signed in 1998.

But Mr Biden’s trip is overshadowed by the fact that Northern Ireland’s power-sharing government is not functioning.

It collapsed last year when the Democratic Unionist Party (DUP) – one of the biggest parties at Stormont – pulled out as part of a protest against post-Brexit trade rules for Northern Ireland.

Mr Biden arrived in Belfast city centre at about 22:20 BST on Tuesday after making the journey from the airport in his presidential motorcade.

He stayed overnight at a Belfast hotel before the main event of his visit to Northern Ireland, a speech at the new Ulster University campus in Belfast.

He is expected to emphasise the willingness of the US to help to preserve what he sees as the peace and prosperity gained since the Good Friday Agreement.

The president is also expected to talk about how the US administration can support Northern Ireland’s economy.

US Secretary of State Anthony Blinken tweeted that he was joining President Biden in Belfast “for engagements on shared economic prosperity”.

A huge security operation is under way, with many city centre streets closed.

Bedford Street, York Street, Donegall Street, Frederick Street and Great Patrick Street are closed to traffic with restrictions on Dunbar Link.

There is a heavy police presence on the ground but the Police Service of Northern Ireland hopes roads will be reopened in time for the evening rush hour.

Meanwhile, BBC Radio Ulster’s The Nolan Show has been shown a document marked “PSNI and sensitive” which appears to give details of the security operation.

It lists and names police officers in charge of the area around Mr Biden’s hotel and was found lying on a street by a member of the public.

The PSNI said it was investigating a security breach and would put “appropriate actions in place”.

“We take the safety of visiting dignitaries, members of the public and our officers and staff extremely seriously,” it said.

Ahead of his arrival, Mr Biden said he was looking forward to marking the anniversary in Belfast and “underscoring the US commitment to preserving peace and encouraging prosperity”.

His trip to Belfast will be the first leg of a four-day stay in Ireland, during which he will also discuss his Irish roots and meet Irish relatives. His sister Valerie and his son Hunter are also accompanying the US president on the visit.

Amanda Sloat, a member of Mr Biden’s National Security Council who is in Belfast for the visit, said his meeting with Mr Sunak would be an opportunity to discuss the tremendous progress made in Northern Ireland since 1998.

She added they would also discuss “how the United States can continue working with the UK government, as well as the Irish government, the European Union and Northern Ireland’s leaders to continue to be a partner for peace and to support continued economic development in Northern Ireland”.