A hard border in Ireland must be avoided, the Taoiseach has urged the British prime minister.
Leo Varadkar and Rishi Sunak spoke by telephone on Monday as talks between the UK and EU continue around the Northern Ireland Protocol.
It is the first conversation by telephone the two premiers have had since Mr Varadkar became Taoiseach last month.
The post-Brexit treaty was agreed between the two sides in 2019 to see regulatory and customs checks on goods moving between Britain and Northern Ireland to avoid a hard border on the island.
However unionists have opposed the protocol, claiming it has distanced Northern Ireland from Britain.
The DUP has refused to enter the Stormont Assembly until unionist concerns are dealt with.
The ongoing stalemate in Belfast was among discussions between the two premiers, in what has been described as a “good conversation”.
A Government spokesperson indicated Mr Varadkar and Mr Sunak discussed a range of issues including the protocol, Stormont and British-Irish relations more broadly.
They indicated that both recognised the importance of the ongoing engagement between the EU and the UK on the protocol.
The Taoiseach is described as having repeated the need for a solution which avoids a hard border on the island of Ireland and protects the integrity of the single market.
They also spoke about the positive cooperation between the EU, UK and US in responding to the war on Ukraine and discussed the impact of the proposed introduction of Electronic Travel Authorisation on third country nationals travelling across the border.
Meanwhile, Mr Varadkar also reiterated his Government’s concerns about the draft legislation around dealing with Northern Ireland’s troubled past, which is currently making its way through the Westminster legislative process.
A Downing Street spokeswoman said both leaders reflected on the need for Northern Ireland to have a power-sharing government up and running as soon as possible, and agreed to stay in close touch.