Northern Ireland businesses trading across the Irish border should contact the Irish government for advice in the event of a 'no-deal', said the Brexit secretary.
Dominic Raab made the comments on Thursday.
He was releasing the first of a draft of government papers, described as EU Exit Technical Notices.
The documents cover a variety of sectors including medicine, finance and farming.
Mr Raab reiterated that the government would not pull back from previous commitments on Northern Ireland.
Analysis: 'Little comfort for NI businesses'
by Julian O'Neill, BBC News NI Business Correspondent
Uncertainty. Has there been a word more commonly used by Northern Ireland business for two years?
Organisations had hoped the Brexit papers would bring some clarity around what happens if there is no deal.
Instead, many were left unimpressed.
Manufacturing NI said the guidance to contact the Irish government for advice was "extraordinary".
The Northern Ireland Chamber of Commerce was just as damning.
It said businesses will look at the papers and conclude they "confuse them more".
So 25 documents published, with more to come: a lot of paper, but little by way of comfort for NI businesses.
The minister said reaching a deal with the EU was the "overriding priority" and "by far the most likely outcome" but that "we must be ready to consider the alternative".
Mr Raab said the papers "set out the practical information that we think Northern Ireland businesses should look at," in the case of a 'no deal' situation.
Analysis: 'Not much new for farming'
by Conor Macauley, BBC News NI Agriculture Correspondent
The Brexit no-deal scenario papers on farming tells us essentially what we already knew.
The government has previously committed to the same level of financial support for farmers until the end of this Parliament - expected to be 2022.
Under the Withdrawal Act, the UK legislation is being prepared to continue existing farm payments until new domestic agriculture policies are agreed for the devolved nations.
Farmers would have to comply with current standards and inspection regimes to qualify.
The same commitment would apply to things like agri-environment schemes and rural support projects under the Rural Development Programme - part-funded by the EU.
Organisations which secure funding through such programmes between now and the end of 2020, will be guaranteed payments for the lifetime of the scheme by the UK.
Responding to a question about whether there was to be a special arrangement for Northern Ireland, Mr Rabb said: "I think we're saying very loud and clear that we will not allow anything to disrupt the terms of the Belfast agreement.
"We wouldn't want to return to any form of hard border at the border."
Mr Raab added: "That's a clear commitment and we have no intention of relenting from it."
The papers also warn that the cost of credit and debit card payments between the United Kingdom and the European Union would be likely to increase, and that the current ban on surcharges would not apply should no deal be reached.
It is also likely that processing times for euro transactions would also be much slower.
Irish foreign minister Simon Coveney insisted the announcement was "a matter for the UK government".
"It should never be forgotten that Ireland will continue to enjoy the benefits of our EU membership after Brexit," he added.
"Everyone's focus though should be on getting a deal on a sensible Brexit which must include the Irish backstop agreed last December."
Political parties in Northern Ireland have reacted to the release of the papers.
Alliance Brexit spokesperson Stephen Farry said it was "farcical" for the UK government to suggest businesses trading across the Irish border should contact the Irish government for advice in the event of a no-deal.
Ulster Unionist Party (UUP) leader Robin Swann said he had spoken to Northern Ireland Secretary Karen Bradley seeking clarity about the issue of Northern Ireland and cross-border trade.
"As we approach the endgame in terms of Brexit negotiations, it is essential that as much clarity and certainty as possible are reached with regard to trade between Northern Ireland and the Republic of Ireland," he added.
SDLP Brexit spokesperson Claire Hanna said the "absence of the backstop" in any of the publications was "an extremely worrying development".