Watch live as Joe Biden leaves Joint Base Andrews in Maryland as he departs for a four-day visit to Northern Ireland and Ireland in a trip marking the 25th anniversary of the Good Friday Agreement.
The US president has been "very excited" to visit Ireland for "quite some time" and is "more than comfortable" making the trip despite recent security concerns, White House spokesperson John Kirby said.
The trip comes after MI5 raised the terrorism threat in Northern Ireland to "severe," meaning an attack is highly likely.
Mr Biden's is visiting to mark 25 years since the signing of the peace deal that largely ended the Troubles.
The conflict, beginning in the late 1960s, was between republicans who wanted Northern Ireland to become part of a united Ireland and unionists who wanted it to remain within the UK.
The Good Friday Agreement was made between the British and Irish governments and eight political parties in Northern Ireland.
US Senate majority leader George Mitchell helped broker the deal, chairing talks between parties and groups.
The agreement acknowledged the constitutional status of Northern Ireland as a part of the UK, but established a principle of consent which meant that a united Ireland could be established if and when a majority of people in the Republic of Ireland and Northern Ireland wanted it.
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