Sinn Fein is expected to outline the party’s next move after powersharing talks in Northern Ireland broke down.
Democratic Unionist leader Arlene Foster has urged the UK Government to set a budget and make policy decisions in the absence of a devolved executive at Stormont.
The talks collapsed after the parties failed to clinch agreement on touchstone issues such as treatment of the Irish language.
Sinn Fein’s Northern Ireland chief Michelle O’Neill said the party had stretched itself and blamed the DUP for collapsing a process aimed at rebuilding coalition government at Stormont after a 13-month suspension.
The British Government faces the prospect of having to step in and take previously devolved decisions in Northern Ireland.
Stormont departments have been without ministers for months and decisions need to be made speedily about the next financial year’s public spending budgets.
Proposals for dealing with Northern Ireland’s violent past involving extra money for historic investigations and truth-telling processes have also been delayed by the impasse and may fall to Westminster to implement.
Ms Bradley said “substantive progress” had been made but conceded “this phase of talks has reached a conclusion”.
The Irish Government, co-guarantor of the 1998 Good Friday Agreement which largely ended violence, has said there can be no return to the direct rule of the period before that landmark accord.
Taoiseach Leo Varadkar said in a statement: “I very much regret the statement from the DUP. Power sharing and working together are the only way forward for Northern Ireland.”