The delay could push back the Queen's Speech, initially scheduled for next Monday.
British Prime Minister Theresa May's Conservative party resumed talks on a deal to prop up her minority government on Wednesday as she faced a battle over her Brexit strategy just days before European Union divorce talks are due to begin.
The EU will keep the door open for Britain to return, but only on worse terms than it now has, European Parliament Brexit negotiator Guy Verhofstadt said Wednesday. May has said the divorce talks, likely to be the most complex in Europe since World War Two, will begin as planned next week and her Brexit minister, David Davis, said Britain's negotiating position was unchanged.
The announcement by Brexit Secretary David Davis and European Union negotiator Michel Barnier follows preliminary talks in Brussels between officials.
The prime minister met leaders of Northern Ireland's other political parties on Thursday, some of whom had voiced concerns that a tie-up could destabilise local politics and undermine the British government's neutrality in overseeing separate talks to form a new power-sharing government in Northern Ireland.
Ms May is now engaged in talks with the Democratic Unionist Party over a so-called "confidence and supply" arrangement that give the Conservatives a majority in the House of Commons and the ability to form a government.
The DUP and Sinn Fein are taking part in Thursday's talks at Downing Street, along with smaller parties.
Lyon in 'advanced talks' to sign Chelsea forward Bertrand Traore
Burkina Faso global Traore signed a new three-year contract at Chelsea in 2016, and made 12 appearances for Chelsea in 2015-16. Speaking at a press conference, Aulas said: "We want to bring Bertrand Traore to the club".
Speculation has mounted that an agreement will be hard to reach due to the deal now being negotiated between the DUP and Conservative Party to support the Tory government.
Mr Brokenshire insisted the Government would honour its commitments in the Good Friday Agreement and warned that time was running out if powersharing was to be restored and a return to direct rule from Westminster avoided.
"We continue to work with all the parties in Northern Ireland and the Republic of Ireland in ensuring that we can continue to put in place those measures necessary to fulfil those agreements, " she said.
Meanwhile, talks are continuing between the DUP and Conservatives, to secure the support of the DUP's 10 MPs in steering government business, including crucial measures on Brexit, through the Commons.
Despite Downing Street having announced last Saturday that a deal with the DUP had been struck, there are now suggestions that no agreement may be finalised this week.
Speaking yesterday Secretary of State for Northern Ireland James Brokenshire said that the United Kingdom government would do everything they can to restore the power-sharing institutions.
But speaking in Dublin after a meeting with the new Taoiseach Leo Varadkar, the DUP leader Arlene Foster said it was down to Sinn Fein whether an agreement is reached.