New Irish premier Simon Harris has emphasised his commitment to Anglo-Irish relations and support for Ukrainian sovereignty, after calls to UK Prime Minister Rishi Sunak and Ukrainian President Volodymyr Zelensky.

Mr Harris and Mr Sunak discussed the humanitarian crisis in Gaza, the war in Ukraine, the resumption of powersharing in Northern Ireland, developments since Brexit and the recent North-South Ministerial Council.

Mr Harris said that “the British-Irish relationship is of huge importance” and he would continue to develop it.

Mr Harris also spoke by phone to Northern Ireland First Minister Michelle O’Neill and deputy First Minister Emma Little-Pengelly, saying how important he views his role as a co-guarantor of the Good Friday Agreement.

Wednesday marks the 26th anniversary since the historic peace deal was signed.

“With this week’s re-establishment of the North South Ministerial Council, the Taoiseach and the First Minister and deputy First Minister looked forward to renewed, positive North-South engagement in the months ahead,” a statement said.

Mr Harris also spoke by phone to Ukrainian President Volodymyr Zelensky, and said he is “fully committed to supporting Ukraine’s sovereignty and territorial integrity”.

In a post on Instagram on Wednesday, Mr Harris said that he was “very eager” for talks on Ukraine to begin under the Belgian presidency of the European Council.

On Thursday he flies to Brussels to meet the President of the European Commission, Ursula von der Leyen, President of the European Parliament Roberta Metsola, and Ireland’s EU Commissioner Mairead McGuinness.

He will then travel to Warsaw to meet the Prime Minister of Poland, Donald Tusk, and the President of the European Council, Charles Michel.

Mr Harris also said on Instagram that the Prime Minister of Spain, Pedro Sanchez, will travel to Dublin on Friday so they can discuss “our joint view in relation to the need to recognise the state of Palestine”, adding that he wanted to see progress made on the issue.

During the 20-minute phone call to Mr Sunak, the two leaders committed to holding a bilateral meeting in person in the future, and began with a “warm” discussion about their roles and families.

A Downing Street spokesman said the Prime Minister congratulated Mr Harris on his appointment.

“The Prime Minister and Taoiseach began by reflecting on the strong UK-Ireland bilateral relationship and the shared importance of stability in Northern Ireland,” the spokesman said.

“They agreed that the restoration of the devolved institutions underpinned and deepened the British-Irish bilateral relationship.

“They discussed the strengthening of the economic ties and growth in bilateral trade between the UK and Ireland as the closest of neighbours.

“Turning to the Middle East, they agreed that Hamas should unconditionally release the remaining hostages from the deplorable 7th of October attack on Israel and expressed their grave concern over the worsening humanitarian situation and the need for Israel to accelerate the scale of aid delivered to Gaza.

“The Prime Minister reiterated his position that a two-state solution provided the best basis for a political settlement.

“On Ukraine, the leaders agreed on the vital importance of supporting Ukraine against Russian aggression to defend Ukraine’s sovereignty and protect European security.

“The Prime Minister looked forward to working more closely with the Taoiseach on this important shared priority.

“The leaders agreed to stay in contact in the coming months and the Prime Minister said he looked forward to welcoming the Taoiseach to the UK-hosted European Political Summit in July.”