British Ambassador to Ireland Paul Johnston has described an agreement between the EU and the UK as "significant".
The EU and UK reached an agreement to reset relations yesterday, which British Prime Minister Keir Starmer claimed will add nearly £9 billion (€10.6bn) to the UK economy by 2040.
As part of the agreement, there will be a new sanitary and phytosanitary (SPS) deal on plant and animal products, which will not be time-limited.
Speaking on RTÉ's Morning Ireland, Mr Johnston said it "will make life much easier" for many businesses.
"I think exporters and small businesses, particularly, will notice a big difference once we get the so-called SPS agreement, the agreement that will reduce massively the amount of bureaucracy and checks that exporters have to go through.
"About 100,000 British companies export to the EU every year, many of them, of course, to Ireland and of course, the same is true in reverse. So, reducing that bureaucracy, eliminating the checks will make life a lot easier for people, and I'm sure will lead to greater growth in due course," the ambassador said.
Mr Johnston said the deal was the start of an important process.
"What's been achieved yesterday is significant, both in terms of defence and security and mobility for young people, as well as improving their trade relationships.
Watch: EU Commission president Ursula von der Leyen says the agreement is the start of a 'new chapter'
"But it's not the transformational trade deal that changing any of those red lines would be involved. But of course, that's not on the cards, but it is nevertheless significant," he said.
Mr Johnston added that British exports to the EU fell by about 15% in the post-Brexit period.
"So, it's really important for the government’s growth mission ... that we can start to restore some of that volume and I think yesterday's deal will be at the start of an important process," he added.
Mr Johnston said "the British government will have to 'pay to play’ in the jargon in the EU rearmament programme".
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"But I think a lot of defence industries, and I know this from my time in Sweden and working on European security when I was one of our ambassadors in Brussels, a lot of defence industries and a lot of EU partners will be delighted to see the EU playing a constructive role with Britain in the defence industry and defense security space.
"It's something that's much needed when you consider the threat that Europe faces and I think will be seen as a constructs of an important partner in that area," he said.
In relation to migration, Mr Johnston said that the UK is "absolutely committed to reducing immigration overall and to reducing irregular immigration in particular, and produced a big new White Paper last week with lots of lots of measures on that.
Watch: British Prime Minister Keir Starmer says the summit marks a 'new era' in UK/EU relations
"This is a very different thing. This is a time limited and numerically capped scheme which will allow young people from both the UK and the EU to enjoy the benefits of living, studying in the other country for a temporary period of time.
"And I think that's a good overall thing for the relationship and it will strengthen higher education links and other links between the countries.
"But it's a completely different issue from a widespread freedom of movement operation. it's a specifically limited mobility experience," he said.
Taoiseach Micheál Martin welcomed the outcome of the summit, calling it a "landmark moment".
Mr Martin said the outcomes from the talks deliver on the "shared commitment to reset relations between the EU and the UK".
"The UK is an important like-minded partner for the EU, and for Ireland, sharing our values and commitment to multilateralism and the international rules-based system," he said.
"It is essential that we work in partnership to address global challenges.
"I therefore welcome the conclusion of the defence and security partnership between the EU and the UK at today's summit."
He said the agreements "mark a new beginning in a positive and cooperative relationship between the EU and the UK which is essential for the pursuit of many areas of Ireland's national interest and is an important factor for stability in Northern Ireland".
The UK's decision to extend fishing rights for the EU fishing sector by another 12 years, "also provides certainty to Ireland's fishermen and women", said Mr Martin.
Northern Ireland Secretary of State Hilary Benn also welcomed the EU-UK reset agreement.
He said alignment with EU plant and animal standards will have significant benefits for businesses in Northern Ireland and Britain.
