The UK's lead Brexit minister has called on the EU to "shake off any remaining ill will" over the UK's decision to leave the organisation.
Lord Frost said the EU's previous threat to block vaccine exports had "significantly undermined" post-Brexit measures in Northern Ireland.
He insisted the UK's unilateral move to extend grace periods on border checks was legal under the Brexit trade deal.
The EU disputes this, and is preparing to launch a legal challenge.
The UK has said it will delay new checks on goods arriving into Northern Ireland from Great Britain, agreed as part of the UK's withdrawal deal.
EU Commission Vice-President Maroš Šefčovič has called it a "violation" of the part of the deal relating to Northern Ireland and said legal action was imminent.
Writing in the Sunday Telegraph, Lord Frost insisted the delayed border checks was a "temporary" measure justified to implement the so-called Northern Ireland Protocol.
The Cabinet Office minister added that the measures were justified by the "fragile" situation in Northern Ireland.
"They are about protecting the everyday lives of people in Northern Ireland, making sure they can receive parcels and buy the usual groceries from the supermarket.
"Without this threat of disruption, we can continue our discussions with the EU to resolve difficulties arising from the Protocol constructively," he added.
Northern Ireland has remained a part of the EU's single market for goods, so products arriving from Great Britain have to undergo EU import procedures.
Both sides agreed the arrangement as part of the Brexit withdrawal deal, to avoid the need for border checks between NI and the Republic of Ireland.
But it has led to disruption to some food supplies and online deliveries from Great Britain to Northern Ireland, increasing tensions with the EU.
Source: BBC
