Michelle O'Neill, Sinn Féin's new leader in Northern Ireland, and Democratic Unionist Party leader Arlene Foster are to outline their differing views on Brexit to British Prime Minister Theresa May on Monday, it has been confirmed.
Ms O'Neill and Ms Foster will discuss Brexit-related issues with Mrs May in Cardiff before the British prime minister travels to Dublin for talks with the Taoiseach.
Ms O'Neill formally took over as successor to Martin McGuinness last Monday.
The Sinn Féin party she now leads in Northern Ireland is opposed to Brexit and says it will have negative consequences for the island of Ireland.
Ms Foster's DUP was the only major party in Northern Ireland to campaign in favour of the UK leaving the EU.
The two leaders are to travel to Cardiff on Monday when Mrs May will hold discussions with representatives of the devolved administrations from Scotland, Wales and Northern Ireland.
It will be the first time for Ms Foster and Ms O'Neill to be part of such high-level discussions since the change in the Sinn Féin leadership.
The British prime minister will be offered further reflections on the Brexit issue when she travels from Cardiff on Monday afternoon for her meeting with Taoiseach Enda Kenny.