First Minister Paul Givan has said there has to be progress made "imminently" in negotiations between the Briitsh government and the EU over the Northern Ireland Protocol.
Mr Givan was speaking after he and Deputy First Minister Michelle O'Neill had a meeting with British Foreign Secretary Liz Truss, who is leading the negotiations with the EU.
He said: "In that update Liz Truss has indicated that she is making progress with the European Union and obviously February 21 is a very significant date in terms of what progress will have been made or not made.
"I pressed the foreign secretary about the need to take action in the absence of there being progress and an agreed outcome with the European Union.
"The foreign secretary indicated that the UK government does stand ready to take action, she mentioned the use of Article 16, but she prefers to get an agreed position with the European Union.
"I have emphasised the absolute critical nature of that progress being made, because the protocol is causing instability to these institutions, it is damaging our economy and this is having a real impact on Northern Ireland.
"So, we need to see that progress, we need to see that imminently and we also need to see action taken by the UK government if there isn't an agreed outcome."
Mr Givan said he hopes he is still first minister this time next week.
His party leader Sir Jeffrey Donaldson warned he could not guarantee Mr Givan would still be in position in the coming days with the DUP demanding changes to the Northern Ireland Protocol.
Sir Jeffrey has repeatedly threatened to withdraw ministers from the powersharing Executive - a move that could collapse devolution - if major changes to the Irish Sea border trading arrangements are not secured.
Mr Givan said: "I hope that I am still in this position next week because there are huge issues that we need to deal with as an Executive.
"There are decisions that need to be taken around Covid restrictions on February 10. I have also said we are giving an apology to the victims of sexual abuse in March, I want to be able to do that.
"I also want to be able to deal with the cost of living. That all requires a functioning Executive to be in place.
"That is why it is critical the UK government take action, why it is critical they get an agreed position with the European Union, and if they don't get that then let the UK government take action because the people of Northern Ireland need us to be here delivering on all those issues."
Mr Givan said the British government had named February 21 as a "significant date now because the Joint Working Committee is going to be meeting.
"That will obviously implement any agreed position that they reach with the EU, but with the absence of that agreement we need to see the UK government taking action.
"That is why I was pleased that the foreign secretary did mention in the meeting around the use of Article 16 as a measure that is still available, a safeguard there that the UK Government can deploy and we do need to see progress made."
Deputy First Minister Michelle O'Neill said that Liz Truss has reaffirmed that there is a "deal to be done" by the British government and the EU over the Northern Ireland Protocol.
Speaking after a meeting with the British foreign secretary, Ms O'Neill said: "It was a repeat of what has been said before, they are very much continuing to talk.
"Liz Truss repeated her words that there is a deal to be done, that she is working to find solutions.
"But that is yet to be seen in terms of striking an agreed way forward.
"I encouraged her to listen very carefully to the views of those in the community and voluntary sector that she will meet with.
"She needs to hear loud and clear that the DUP do not speak for the majority here.
"She needs to hear loud and clear that triggering Article 16 serves no purpose other than to cause more uncertainty and she needs to hear the reality on the ground that the majority here want the protocol to work and they want solutions to be found."
On the prospect of Edwin Poots taking unilateral action to halt the port checks, Ms O'Neill said: "Edwin Poots himself has clearly said in the Assembly chamber that he has a legal responsibility in which to administer the checks at the ports, that remains the case today.
"There's also very clear Executive policy that it is the Daera department, his department, that must administer those checks. So, he is the minister responsible.
"So, instead of electioneering and stunt politics he should get on with doing his job.
"That's why I have made that point very clear to him. So, this is all about the election, folks, this is what the DUP are at, it's more stunts in a long list of stunts over the past number of months on this issue."
Ms O'Neill added: "Edwin Poots has played this card before, he's played this hand before and he's failed. It's very, very clear, we have very consistently clear attorney general advice.
"He himself has repeated that claim in the Assembly chamber that he has the legal responsibility to deliver the checks at the ports, as per the Withdrawal Agreement.
"He was designated by the Executive by all ministers agreed that he was the minister responsible to bring that forward. So, that's why this is only stunt politics.
"That's why this is all about yet another staging post for DUP and their election campaign. He has a responsibility, and the (Daera) permanent secretary has responsibility, regardless of what the minister says, that they have to deliver upon the checks because that is an international agreement."
Mr Givan said his party colleague Mr Poots will act to halt Brexit checks at ports.
Having failed to secure a vote on Executive approval for the checks at today's meeting of the administration, Mr Givan said Mr Poots was obliged to ensure he complied with his legal responsibilities.
"Sinn Féin should have allowed this on the agenda today," he said.
"That would be the democratic process. The fact that they have blocked it from getting onto the paper speaks to this wider issue about not recognising that unionists do not consent to the arrangements that the protocol have put in place.
"So, I think that's a mistake on the part of Sinn Féin not to have allowed it into the Executive because for those checks to continue requires the Executive to agree that - that's why we believe that the checks continuing would be unlawful.
"That requires Edwin Poots as the minister to act in a way that will resolve that issue and Edwin Poots is going to act.
"So, the fact that it's not on the agenda does not change the legal parameters by which Edwin Poots as a minister has to discharge his duties and he will be taking action.
"That is something that the DUP have said that we were going to do and we are going to do that."
Mr Givan said civil servants would be obliged to follow any instruction from Mr Poots to halt the checks.
"Absolutely, they'd be obliged to do to it, it's a ministerial instruction to the civil service," he said.
"It's politicians who are elected, they have a democratic mandate, civil servants do not have a democratic mandate to take these decisions and, absolutely, civil servants will have to follow the democratic ministerial instruction of their minister.
"Not to do that, I think, would have profound implications in terms of how the civil service operates."
