A Downing Street spokesperson said:
Yesterday evening the Prime Minister spoke to the Taoiseach on the Brexit negotiations and the situation in Northern Ireland.
The PM reaffirmed our commitment, as set out in the Joint Report, to avoiding a hard border between Northern Ireland and Ireland or between Northern Ireland and the rest of the United Kingdom and to converting all of these commitments into legal text in the coming months.
The PM and the Taoiseach both agreed that it was their preference to achieve this through the overall future relationship between the UK and the EU. The PM advised that she would say more on this future relationship in her speech on Friday.
The leaders also discussed the current political situation in Northern Ireland. The Prime Minister said she had met with both Sinn Fein and the DUP last week and that she still believes a basis for accommodation remains. They committed to remain in touch on this.