The Foreign Secretary has urged the DUP to "get on with it" and restore Stormont after the UK government tabled legislation to override the Northern Ireland Protocol.
Liz Truss said she wants Northern Ireland's power-sharing institutions to resume "as soon as possible" following the publication of the bill to scrap parts of the Brexit deal on Irish Sea trade.
But DUP leader Sir Jeffrey Donaldson said they need to see the bill "moving forward" through Westminster before taking any steps to end their veto on re-establishing the Stormont Assembly or Executive.
Read more: Boris Johnson ripping up Brexit protocol is ‘a new low’ says Micheál Martin
The Northern Ireland Protocol Bill, which was tabled on Monday, aims to ease checks on goods arriving into Northern Ireland from Great Britain.
But the proposed legislation, which has been heavily criticised by the EU and Irish government, could face strong opposition at Westminster amid claims it would breach international law.
Sir Jeffrey said: "There is a stark choice here for parliament.
"The Northern Ireland Protocol and Good Friday Agreement cannot exist together. One seriously harms the other."
He added: "Parliament can either choose to go forward with the [Good Friday] Agreement and the political institutions and stability in Northern Ireland, or the Protocol, but it can't have both."
The Lagan Valley MP said the bill was "real progress" but added: "We need to see the bill moving forward now. We need to see it going through its parliamentary stages."
He told BBC Radio Ulster's Good Morning Ulster programme: "We need this bill to progress as quickly as possible, and we will make our judgements based on the bill going forward and providing the solution that Northern Ireland needs."
Ms Truss said the British government expects to see the Stormont parties form an Assembly and a power-sharing Executive "as soon as possible".
Asked about the DUP, she added: "I would like them to get on with it as soon as possible."
The Protocol agreement between the UK and EU requires regulatory checks and customs declarations on goods moving from Great Britain to Northern Ireland.
Unionists have strongly opposed to the international treaty, claiming it has undermined the region’s place within the United Kingdom.
The DUP has blocked the formation of a new power-sharing government at Stormont following last month's Assembly election in protest.
A majority of MLAs on Monday signed a joint letter to Prime Minister Boris stating their opposition to the proposed legislation to override the Protocol.
Sinn Féin vice-president Michelle O'Neill accused the DUP of "punishing the public" and said the party's boycott was untenable.
Speaking on RTE’s Morning Ireland programme, she referenced millions of pounds in public funding which has not been allocated due to the absence of a fully functioning Executive.
"Here we are, 41 days post-election, and the DUP are denying the public access to funds that we could actually put into their pocket to help them to get through this period. I just don’t think that’s acceptable at all," she said.
"I just think it’s unfathomable that the DUP are adopting the stance and punishing the public by staying out of an Executive that could actually help people through this cost-of-living crisis.
"That is not a tenable position for them to take.
“The rest of us are there every day, all the other parties who want to work together, who want to form an Executive believe that we can do all of that."
Ms O'Neill accused the Prime Minister of a "reckless approach" and urged the British government to "find agreed solutions" with the EU to any issues with the Protocol.
Read more: Boris Johnson ripping up Brexit protocol is ‘a new low’ says Micheál Martin
Read more: Boris Johnson says plan to amend NI Protocol is 'not a big deal'
For the latest politics news straight to your inbox, sign up to our newsletter here.
