A failure to reach a power-sharing deal at Stormont is a “monumental failure” by Theresa May and sets back decades of work, Sinn Féin has said.
The party’s northern leader, Michelle O’Neill, said it was a “consequence of the DUP” supporting a minority Tory government.
DUP leader Arlene Foster said her party would “keep working over the summer”.
It is understood the British and Irish governments will make a joint statement to park the talks.
Northern Ireland has been without a functioning devolved government since January, when the coalition led by the two biggest parties, the DUP and Sinn Féin collapsed, over a green energy scandal.
On Monday, Northern Ireland Secretary James Brokenshire said a deal to restore power sharing was still achievable.