DUP leader Sir Jeffrey Donaldson confirmed his team of MLAs will attend Stormont on Friday to sign the roll.
However, he has yet to make a decision on if his party will nominate a speaker, saying that will come just moments before all MLAs are set to join together for the first time since the election.
"We are committed to making the political institutions work but we're also clear that we need to see decisive action by the government," he said.
Asked whether his party will nominate a speaker, he said: "Our Assembly group will meet and come to final decisions in all of this tomorrow morning.
"The Assembly meets tomorrow morning and parliamentary protocol determines that the first people to know are the people who actually sit in an Assembly, therefore we will make our position clear on this.
"We recognise that these issues need to be dealt with. As a party we have been decisive, we have made our position clear and will continue to do so."
It comes as Sinn Fein's Michelle O'Neill said the Assembly will sit on Friday and "all parties should turn up, all parties should nominate and we should have an Executive up and running".
She added: "There is no reason for that not to happen and it's not acceptable or not good enough that the DUP won't turn up or won't nominate for position of speaker of the title of first and deputy first ministers.
"The public that I have been speaking to today, they want an Executive, they want an Assembly, they want it working for them, they want money in their pockets to deal with the cost of living crisis and we can do all of that while trying to make the smooth implementation of the protocol.
"We will not be held to ransom by the Tory Government... we are all being held to ransom here and that is not acceptable."
It has been reported the Attorney General has given the prime minister legal cover to scrap parts of the protocol.
Asked if he believed the text of the Northern Ireland Protocol needed to be changed, Prime Minister Boris Johnson said: "Look, Northern Ireland is an incredible place, it's got a fantastic future.
"At the moment, very sadly, the institutions of democracy, the political governance of Northern Ireland, has collapsed.
"The institutions set up under the Good Friday Agreement aren't functioning. The executive, the assembly - they can't form.
"That's a bad thing at any time, that's a bad thing now when the people of Northern Ireland need leadership, they need a regional, a provincial government that will focus on the cost of living, on healthcare, on transport, on things that matter in their everyday lives.
"They haven't got that. That's a real, real problem. And the reason they don't have that is because there's one community in Northern Ireland that won't accept the way the protocol works at present - we've got to fix that."
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