Technology can create a "non-visible" border between Northern Ireland and the Republic, Brexit Secretary David Davis has said.
In an update to the House of Commons, Mr Davis said he was quite confident that the use of technology can make the border as "light touch as it is today".
He also revealed that he had visited the "open" US/Canadian border at Detroit to potentially replicate some of the same techniques there on a post-Brexit border in Ireland.
Both Taoiseach Leo Varadkar and Foreign Affairs Minister Simon Coveney have ruled out technology as an option for the border post Brexit.
"I am confident that using the most up-to-date technology, we can get a non-visible border operational along the border between Northern Ireland and Ireland," Mr Davis said.
"That was one of the reasons that I went to Detroit, not so that we can replicate what’s in Detroit but that we can use some of the same techniques, Authorised Economic Operators, pre-notification, electronic tagging of containers, all of those things will make it possible for the Border to be as light touch as it is today."
Mr Davis also said a row over how much money Britain should pay the European Union when it leaves the bloc will most probably go on for the duration of the EU exit talks. He said the two sides had very different legal stances over the so-called Brexit bill.
"My expectation is that the money argument will go on for the full duration of the negotiation," he said.
Mr Davis also said that there was widespread agreement across the European Union about having an implementation period when Britain leaves.
Meanwhile, former Northern Ireland Secretary Peter Hain told the House of Lords that the UK government was proposing a Brexit for the "ideological hard right", and that it was "ignorantly indifferent" to the peace process.
He said that the UK should remain in the single market, but if that isn’t a runner, Northern Ireland should.
"In my view the only way of resolving the border conundrum is for Northern Ireland to be within the same customs union and single market as the Republic: either Northern Ireland alone or preferably the whole of the UK," he said.
He accused the British government of "cynically dumping the border problem on Brussels".
"The reality is that once the UK leaves the Customs Union in less than two years’ time the relationship between Northern Ireland and the Republic of Ireland will fundamentally change."
Former First Minister David Trimble urged the Government to stop talking and briefing on money.
"Finally, a personal observation, something that worked very well for myself. That is, if you’re not prepared to walk away, you have no leverage," he said.
"But you must be prepared to, for the insults that will follow."
Meanwhile, Labour has announced its MPs will vote against the key piece of legislation taking Britain out of the European Union.
Michel Barnier’s claim that “genuine progress” had been made on Irish matters in the latest round of Brexit talks was a rare moment of positivity in a news conference that laid bare the gulf between the UK and EU.
The European Union's chief Brexit negotiator said on Thursday no "decisive progress" had been achieved in the third round of Brexit talks, and that opening talks on the two sides' future ties in October was doubtful at the current pace.