Taoiseach Simon Harris has said that British Prime Minister Keir Starmer has accepted his invitation to visit Dublin on 7 September.
Mr Harris was at Chequers for a bilateral meeting with Mr Starmer, where the Taoiseach said that the two men have agreed to hold a summit every year led by the leaders.
"From that summit, our work programme would flow," he said. He called this "significant" progress.
In relation to Ireland withdrawing its interstate case against the UK, the Taoiseach said that it was too early to say but that both governments would work constructively on it.
Speaking after their meeting, the Taoiseach said: "I am really pleased to confirm that the reset I have been speaking about in terms of Anglo-Irish relations is real.
"It is under way and it is meaningful.
"We discussed Northern Ireland, we discussed issues in relation to the EU and the UK's relationship with the European Union.
"We discussed international issues in relation to Ukraine and Gaza.
"We have also agreed to put in place a structure where the British and Irish governments each year would have a summit led by the Prime Minister and myself where we could focus on key issues.
"From that summit a work programme would flow which we would task various ministers with taking forward with their counterparts.
"This, I believe, is all really significant and substantive progress."
Leaders exchange gifts
A Donegal jersey was presented by the Taoiseach. Mr Starmer also received one shortly after he got married.
Mr Starmer has one from a trip to Donegal shortly after he got married and he still wears it.
The Prime Minister gifted the Taoiseach a Downing Street whiskey decanter set.
Speaking as they arrived, Mr Starmer said that both countries would "move on to the next chapter… a stronger and deeper relationship".
The pair are to discuss efforts to improve Anglo-Irish relations.
Mr Starmer said that he was pleased to have the opportunity to "reset" the UK's relationship with Ireland.
"I am very pleased to have this very early opportunity to, what I see as resetting, strengthening and deepening our relationship," he said before the two leaders were due to have a working dinner along with their officials.
The Taoiseach responded: "I am delighted to be here too, to congratulate you in person. It means a lot to us, a lot to Ireland."
Mr Harris is the first international leader to visit the UK since Mr Starmer was elected prime minister.
Both leaders have reaffirmed their commitment to the Good Friday Agreement and speaking ahead of travelling to the UK, the Taoiseach said that the reset in the relationship had to be more than just a slogan.
"I am fully committed to a stronger, mutually respectful and ambitious partnership between both countries, and to getting down to work to make this happen," Mr Harris said.
However, Sinn Féin leader Mary Lou McDonald has said Mr Harris must push for a public inquiry into the murder of Belfast solicitor Pat Finucane when he meets Mr Starmer.
The Taoiseach's visit to the UK coincides with the UK's official state opening of parliament and the king's speech.
Forty separate pieces of legislation were announced in the speech, including a commitment by the British government that it will repeal and replace the Northern Ireland Legacy Act.
In its manifesto launched during the recent general election campaign, the Labour Party committed to repealing and replacing it "by returning to the principles of the Stormont House Agreement, and seeking support from all communities in Northern Ireland".
Mr Harris had said in advance of his visit to Chequers that he expected to discuss Northern Ireland as well as the situations in Gaza and Ukraine during his meeting with the prime minister.
He has previously committed to being an ally of the UK when it comes to efforts to improve its relationship with the European Union and he is expected to update the prime minister on EU priorities.
The pair will meet again tomorrow, when leaders from across Europe gather for the European Political Community Summit in Oxfordshire.
Additional reporting PA
