The White House has voice concern at the continuing violence in Northern Ireland.
Thursday night saw disorder return to the streets of Belfast at the Lanark Way interface after a week of violence in mainly loyalist areas over the past week.
White House press secretary Jen Psaki addressed the violence during a press conference on Thursday.
“We are concerned by the violence in Northern Ireland and we join the British, Irish and Northern Irish leaders in their call for calm," she said.
“We remain steadfast supporters of a secure and prosperous Northern Ireland in which all communities have a voice and enjoy the gains of the hard-won peace.
“We welcome the provisions in both the EU-UK trade and cooperation agreement and the Northern Ireland protocol which help protect the gains of the Belfast/Good Friday Agreement.”
Taoiseach Micheal Martin and Prime Minister Boris Johnson have called for calm.
The pair spoke over the phone on Thursday afternoon.
A statement from the Irish Government said: "Stressing that violence is unacceptable, they called for calm.
"The way forward is through dialogue and working the institutions of the Good Friday Agreement.
"They agreed that the two governments would continue to stay in contact."
The Secretary of State for Northern Ireland Brandon Lewis has called for parties in Northern Ireland to "work together" in order to ease tensions. He is to meet local leaders on Friday.
Irish Foreign Affairs Minister Simon Coveney said he was also reaching out to the parties.
He said it was a time for calm and unity.
He said he and the EU had been listening to the concerns round the NI Protocol and how they can be addressed "in terms of implementation".