New Prime Minister Rishi Sunak has told Taoiseach Micheal Martin that he would prefers a “negotiated outcome” to issues caused by the Northern Ireland Protocol.
The two leaders held a phone conversation on Wednesday evening.
Mr Martin said they discussed the need to find “agreed solutions” on the protocol.
The post-Brexit trading treaty, which is fiercely opposed by unionists in Northern Ireland, has led to the collapse of the Stormont Assembly and Executive.
The DUP has said it will not engage with the devolved institutions in Belfast until decisive action is taken to remove the protocol’s economic barriers on trade between Great Britain and Northern Ireland.
The Government has vowed to secure changes to the protocol, either by a negotiated compromise with the EU or through proposed domestic legislation – the Northern Ireland Protocol Bill – which would empower ministers to scrap the arrangements without the approval of Brussels.
The European Commission has warned that such unilateral action at Westminster would be in breach of international law and could prompt retaliatory action.
Following his conversation with the Prime Minister, the Taoiseach tweeted: “Good conversation with British PM @RishiSunak this evening.
“Discussed co-operation on Ukraine and ongoing developments in NI.
“Agreed on importance of EU-UK negotiations to find agreed solutions on the protocol.”
A spokesman for the Taoiseach said: “The Taoiseach and Prime Minister Sunak spoke this evening.
“The Taoiseach congratulated PM Sunak on his appointment and looked forward to the two Governments working closely together.
“They discussed cooperation in the response to the Russian invasion of Ukraine.
“They both agreed on the importance of EU-UK engagement to find agreed solutions to the issues around the Northern Ireland Protocol and they discussed ongoing developments in Northern Ireland.
“The Taoiseach and the Prime Minister reiterated their commitment to a strong British-Irish relationship and looked forward to an early opportunity to meet.”
A Downing Street spokeswoman said: “Prime Minister Rishi Sunak spoke to Taoiseach Micheal Martin this evening.
“The leaders agreed on the vital importance of a strong relationship between the UK and Ireland and expressed their determination to build on that friendship in the coming months.
“The Prime Minister welcomed Ireland’s ongoing support for Ukraine, and the leaders agreed on the importance of continued international unity in the face of (Vladimir) Putin’s aggression.
“Discussing the Northern Ireland Protocol, the Prime Minister set out that his preference remained a negotiated outcome and hoped all parties would approach the current challenges with pragmatism and goodwill.
“The leaders agreed on the urgent need for a functioning executive in Northern Ireland. Both undertook to continue discussions in the coming weeks and months.”
European Commission president Ursula von der Leyen also had a phone conversation with Mr Sunak.
She tweeted: “Very good phone call with UK PM @RishiSunak
“(The EU and UK) are strategic partners.
“Looking forward to working on crucial issues such as Russia’s war on Ukraine and climate change.
“And on finding joint solutions under the (Northern Ireland) Protocol on IE/NI that will provide stability and predictability.”
A Downing Street spokesperson said the leaders had stressed the importance they both place on the relationship between the UK and EU.
The spokesperson added: “The Prime Minister and President von der Leyen agreed that the UK and EU have much in common, not least the challenges we are facing in areas like the economy and climate change.
“They resolved to work closely together to tackle those challenges.”
