Liz Truss is expected to hold talks with Irish premier Micheal Martin about Northern Ireland's Brexit gridlock as he visits London for Queen Elizabeth II's funeral.
The Taoiseach will represent Ireland at the ceremony on Monday that will take place at Westminster Abbey, and is expected to meet Ms Truss afterwards.
It would be their first official meeting since Ms Truss became Prime Minister last week, but they did both attend a memorial service for the late monarch in Belfast on Tuesday.
Mr Martin suggested Queen Elizabeth II's death was an opportunity to "reset" relations between Britain and Ireland following tense confrontations over Brexit.
Micheal Martin is expected to speak to Liz Truss in London.
Oliver Contreras
Liz Truss will hold the talks in a new bid to breach the Brexit impasse.
Victoria Jones
Political tensions in Stormont continue to surge.
Sinn Fein became the largest party at the assembly in May's election but the DUP have refused to restore the power-sharing executive while the Northern Ireland Protocol remains in place.
Ms Truss has also raised the possibility of pushing ahead with legislation in Westminster to scrap parts of the protocol in order to ease negotiations with the EU over trading terms.
Dublin and Brussels have been left angered by the stance taken, with new legal action being launched by the bloc.
Ms Truss was sat beside Mr Martin at a memorial service for Queen Elizabeth II in Belfast.
The Prime Minister engaged in lengthy conversation with the Taoiseach as they waited for proceedings to begin.
Sinn Fein vice president Michelle O’Neill and DUP leader Sir Jeffrey Donaldson were sitting directly behind them.
Irish President Michael D Higgins and his wife Sabina arrived and sat alongside Ms Truss and Mr Martin.