The US President also reiterated his support for the Northern Ireland Protocol, which was negotiated as part of the Brexit deal. Under the terms of the agreement negotiated with the EU, goods arriving from the UK are subject to custom controls at Northern Irish ports. Unionists have argued, however, that the protocol has strained ties with the rest of the UK through the imposition of trade barriers and has inflamed loyalist tensions.
Jen Psaki, the White House press secretary, said: “We are concerned by the violence in Northern Ireland and we join the British, Irish and Northern Irish leaders in their calls for calm.”
She added: “We welcome the provisions in both the EU-UK trade co-operation agreement and the Northern Ireland protocol, which helped protect the gains of the Belfast/Good Friday agreement.”
On Thursday, Northern Ireland Secretary of State Brandon Lewis travelled to Belfast to talk with political leaders at Stormont in an attempt to diffuse the unrest.
He admitted that Brexit had created “real issues” in the country, but said the way to resolve them was through negotiation and not violence.
Mr Lewis told the Northern Ireland Executive: “I’ll be the first to acknowledge over the first few months of the year there were real issues around how the [Northern Ireland] protocol has landed for people, both as consumers and those in the loyalist and unionist community.
“The way to deal with these things is through a democratic and diplomatic, political process.
READ MORE: EU ambassador says Brexiteers have ‘no alternative’ to NI Protocol
Police used water cannon to disperse crowds, after being pelted with petrol bombs, stones and fireworks.
Justine Minister Naomi Long pleaded for calm and condemned the violence as “utterly reckless”.
In a tweet, she wrote: “More attacks on police, this time from nationalist youths.
“Utterly reckless and depressing to see more violence at interface areas tonight.”