The Northern Ireland Secretary has rejected claims by the DUP leader that the government's new Brexit deal with the EU is a "sticking plaster".
Chris Heaton-Harris said the agreement is "a solution to the problems that were produced by the protocol" adding that "it will work".
The DUP voted against the Government on the Stormont Brake element of the Windsor Framework in parliament on Wednesday.
Sir Jeffrey Donaldson said it was his belief that the deal "won't work".
On Thursday, Chris Heaton-Harris met with Stormont party leaders at Hillsborough Castle to discuss the Windsor Framework and the budget that he will have to oversee in the absence of a functioning assembly.
It comes after MPs voted in favour of Prime Minister Rishi Sunak's new deal on post-Brexit trading arrangements for Northern Ireland, clearing its first Commons test. A total of 22 Conservative MPs voted with the DUP against the government.
The DUP leader, Sir Jeffrey Donaldson, said the Windsor Framework "won't work".
"I am not interested in sticking plasters, they don't work and I'm afraid there is in the Windsor Framework an element of the sticking plaster," Mr Donaldson said.
"We're looking primarily to the Prime Minister and to the Government of the United Kingdom," he continued.
"No better place than here at Royal Hillsborough to say to the Government we need to sort this out, we need to get the change that is required to deliver stable sustainable government in Northern Ireland.
He added: "When the Foreign Secretary comes back from Brussels, when the Prime Minister has the time, we'll be sitting down with them along with the Secretary of State and we'll be putting our case."
Speaking to the media on Thursday, Chris Heaton-Harris outlined the nature of his talks with parties.
He said: "We've been talking about the Windsor Framework, how a deal that everybody said that could not be done between the UK Government and the European Union has been done to solve all the practical and many other issues that were caused by the Northern Ireland Protocol of the past, and that that deal is done."
"And that deal is going to be accepted at a joint committee meeting tomorrow and will become international law shortly afterwards. There is no renegotiating of that deal.
The secretary of state added: "Now I think it's down to the communities of Northern Ireland to work out how best it can work for them. I think it can work for them really well.
"I do believe it will herald, alongside the 25th anniversary of the Belfast Good Friday agreement, the next 25 years could be all about prosperity, if everybody puts their shoulder to the wheel."
As for concerns around Northern Ireland's budget, Mr Heaton-Harris said tough decisions would have to be made while the current political impasse continues.
He explained that he believes the budget "is a matter for the executive and it very much should be a matter for the executive to be doing".
"We need an executive up and running for that to happen.
"I do not want to be in a position where I have to set a budget," he added.
"There are going to be some tough decisions to be taken and they should be taken by local politicians, locally elected, democratically elected people for the people they represent.
"But if the executive isn't up and running in short order, then I will be setting a budget in the next few weeks to make sure that public services in Northern Ireland can continue to run."
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