The Foreign Secretary said divorce terms with the EU must be “consistent” across the whole of Britain.
His comments come after Theresa May’s Northern Irish allies the Democratic Unionist Party (DUP) rejected any deal which would distance the region from the UK.
Speaking to reporters after a speech on counter terrorism today, Mr Johnson said: “Whatever way we devise for getting onto the body of the talks, it’s got to be consistent with the whole of the United Kingdom taking back control of our laws, of our borders and of our cash.”
The Government is reportedly prepared to offer the EU up to €50billion to settle the UK’s financial obligations.
And Mr Johnson, when asked if he could understand why people who voted for Brexit might feel betrayed by Britain paying large sums of money to the EU, said the question was “absolutely right”.
The figurehead Leave campaigner has previously said Brussels could “go whistle” over demands for huge sums for the divorce bill.
But he has since conceded the UK will pay an exit settlement, arguing tens of billions will be money well spent if helps “get the ship off the rocks” and move Brexit negotiations forward.
Meanwhile, EU bosses have set the Prime Minister a deadline of midnight Sunday to come up with a workable deal for key divorce issues.
The PM and her team appeared to be on the cusp of securing a deal on Monday, but her plans were torpedoed after a furious response from the DUP.
Unionist leaders, after learning Mrs May was planning on offering “regulatory alignment” with Northern Ireland and the Republic, refused to agree to the deal.
Mrs May spoke with Irish Taoiseach Leo Varadkar and Mrs Foster yesterday, but does not appear to have made any concrete progress, with Westminster, Dublin and Stormont refusing to back down on their demands.
But a senior Irish official said tonight a deal was “very close” and could be wrapped up in a matter of “hours”.
The official told a British Irish Chamber of Commerce event in Brussels: “It is moving quite quickly at the moment. Negotiations are continuing.
“I think we are going to work over the next couple of hours with the UK government to close this off.
“I say hours because I think we are very close.”
However the Press Association has quoted a Government source as saying: “We’re not there yet.”