The UK-EU deal is designed to make trade between Northern Ireland and the rest of the UK smoother. It gives Stormont's Assembly more say over EU rules, and has been welcomed by most Northern Ireland parties, but the Democratic Unionist Party (DUP) remains unconvinced and is still refusing to re-enter power-sharing.
Northern Ireland Secretary Chris Heaton-Harris said the party - Northern Ireland's second largest after Sinn Féin - has yet to come to terms with the significance of Wednesday's overwhelming parliamentary vote in support of the new Brexit deal.
The joint UK-EU body that is overseeing Brexit is meeting to ratify the legal changes brought about by the Windsor Framework. Speaking after meetings with the five main Stormont parties at Hillsborough on Thursday, Mr Heaton-Harris said the deal was done and would soon become international law.
Mr Heaton-Harris' comments came a day after MPs voted by 515 to 29 to support the deal agreed by Prime Minister Rishi Sunak. It will open the door to talks in other areas of cooperation that had been blocked - including financial services and Britain's access to the EU's flagship Horizon research scheme.