However, sufficient progress in the talks with the DUP has been made to allow the state opening to be scheduled, a government source said.
He explained that the two parties are both committed to delivering Brexit, fighting terrorism, preserving the United Kingdom and boosting economic prosperity, giving a clue as to what will be included.
Talks are still on-going between the Conservatives and the Northern Irish party to get their support for a Queen's Speech to be voted through next week.
The leader of Britain's House of Commons says the state opening of Parliament will take place on June 21.
Theresa May has called the Democratic Unionist Party's bluff by announcing a Queen's Speech for next Wednesday without a deal.
DUP leader Arlene Foster, who met Mrs May in No 10 on Tuesday, is understood to have returned to Northern Ireland leaving her deputy Nigel Dodds to represent the party at Thursday's meeting.
Mrs May held talks at Downing Street with the other Northern Ireland political parties in an attempt to allay growing concerns that the expected DUP deal would undermine the peace process.
May needs the support of the DUP to govern, after a disastrous election result in which she lost her parliamentary majority. The decision to set a firm deadline is likely to increase pressure on both parties, particularly the DUP, to reach an agreement.
Andrea Leadsom, the Commons Leader, said: "Whilst our top priority right now is supporting the victims of the awful tragedy at Grenfell tower, we also need to look ahead by setting out a legislative programme that not only delivers a successful European Union exit but also a domestic agenda which aims to tackle the social injustices in our country".
Republican party Sinn Fein have stressed that they will be seeking reassurances over any deal with the unionists.
The 1998 Good Friday Agreement, also referred to as the Belfast Agreement, commits the United Kingdom and Irish Governments to demonstrate "rigorous impartiality" in their dealings with the different political traditions in Northern Ireland.
"We have two weeks from today to get the Northern Ireland executive up and functioning again, and to try to bring in a new chair is actually a waste of time and a distraction", said Mr Swann.