ARLENE Foster believes a Brexit deal can still be secured because the "final part of a negotiation" is the most crucial.
The DUP leader's comments came in the wake of Westminster's vote on Wednesday night to reject leaving the EU without a deal.
The former first minister, who is in the US ahead of the St Patrick's Day celebrations, has had discussions with Taoiseach Leo Varadkar in Washington DC.
While Mrs Foster is Stateside, her party has been in talks with Theresa May's government in London, amid reports it could back the withdrawal deal that MPs have already rejected twice.
Mrs Foster said party representatives had also been in discussions with Attorney General Geoffrey Cox about changes to the deal.
"Nobody wants to leave without a deal and we want to make sure we get there," she told the BBC.
"It's very simple – what it will take to get the DUP over the line is the fact that Northern Ireland is not left behind, the constitutional integrity of the UK is the same and we have a strong say in the future of the UK."
The DUP leader said her party wanted the UK to leave the EU with a deal, but that her party had certain tests it must meet before they will back it.
"Brexit is two weeks away, as I've constantly said, when you come to end of a negotiation that's when you really start to see the whites in people's eyes and you get down to the point where you can make a deal," she said.
Read More: Brexit: UK's no-deal trade plan – and what it means for Ireland north and south
The European Commission has warned there will be no further negotiations or clarifications on the Brexit deal.
Mrs Foster's remarks came as the DUP welcomed the trade plans outlined by the British government on Wednesday in the event of a no deal.
The plan would see tariff-free trade on goods moving south to north. However, goods from the Republic destined for Britain would potentially face high tariffs.
A DUP spokesman said the UK had demonstrated its intention not to impose any border checks or controls.
"The European Union and the Irish government have said they do will not impose checks or controls so this should allay fears which some had been raising about the border," the spokesman said.
"We would expect the announcement on tariffs for goods moving from the Republic of Ireland into Northern Ireland to be reciprocated for those moving in the other direction – it is now up to the Irish Republic to make clear where they stand."
But Ulster Unionist leader Robin Swann said the measures brought the Brexit saga to a "new low".
Read More: Michael Gove warns no-deal Brexit could lead to direct rule
He accused the British government of "desperation" and potentially turning the north into a "smugglers' fantasy".
Meanwhile, DUP MP Ian Paisley has described remarks by Michael Gove that a no deal Brexit could lead to Dublin having more involvement in the north as "insulting".
Mr Gove said on Wednesday that the British government would have to increase engagement with Dublin in the event of no deal.
Mr Paisley challenged the Tory environment secretary in Westminster over whether he "misspoke".
The North Antrim MP claimed Mr Gove had "basically said that more powers would be given to Dublin to be exercised over Northern Ireland".
He also warned cabinet minister David Lidington, saying: "The minister will know how insulting that is to the members who sit on this bench, and... it's the members who sit on this bench that keep his party in power".
However, the Tory leader's de facto deputy said there were "absolutely no plans at all to transfer additional powers or rights to the government of Ireland".
