Brexit: UK wants deal with EU over NI food supply
The UK government is seeking to agree "special provisions" with Europe over the food supply to Northern Ireland from Great Britain.
The environment secretary is seeking to cut a deal limiting trade friction after the Brexit transition.
George Eustice told a Lords scrutiny committee this was an issue for GB supermarkets supplying their NI stores.
Under the Withdrawal Agreement signed by the UK and EU, NI will follow EU rules on goods, including foods.
However, Great Britain will not.
The matter will be discussed at a joint committee of EU and UK representative who oversee the implementation of the treaty.
"I guess the most difficult thing is perhaps around composite loads from supermarkets taking a lorry with multiple products to an individual store in Northern Ireland," Mr Eustice said.
"We will be trying to work out whether there can be special provisions on that, otherwise it will cause quite an issue," he said.
Mr Eustice said as there was no risk of such loads crossing the border, it would be possible to resolve the problem.
Retailers have warned that additional delays, checks and associated costs could push up prices and limit choice for consumers in Northern Ireland.
They had demanded much greater information on what paperwork - some of which can cost up to £200 -and how many physical checks would be required.
Mr Eustice said he was confident that processes could be put in place in time but he conceded the "time is tight".
Committee chair Lord Teverson told the minister that evidence from NI businesses suggested they were "desperate" for greater detail on what processes they might face.
Mr Eustice said the recently published government position paper on the operation of the Northern Ireland protocol offered clarity.
He restated the government's commitment that Northern Ireland agri-food would have "unfettered access" to its key market in Britain.