Fresh talks to restore devolved government at Stormont will start on 16 December, Northern Ireland Secretary Julian Smith has said.
Mr Smith added that, unless agreement is reached by 13 January, fresh Assembly elections will be triggered.
"This one (deadline) is real, January 13 the law changes and an election has to be called in the absence of new legislation," he said.
"Each party had made a commitment to getting back into talks and I think that will happen whatever the situation the week after the election.
"We can't let this run and run, we have got to get this sorted. The number of issues is relatively small.
"There is a deal raring to go, my colleague (Tánaiste and Minister for Foreign Affairs) Simon Coveney has been meeting with Sinn Féin and others this week.
"I have been continuing to meet with the parties in Northern Ireland.
Speaking at the Northern Ireland Conservatives' UK General Election manifesto launch in Co Down, Mr Smith said: "Let's see what the election result is, but in all circumstances every party needs to get back into serious discussions that week before Christmas."
He acknowledged there are a number of issues to deal with.
But he said he does not believe the outstanding issues, including a demand for an Irish language act and calls to reform the petition of concern, are "insurmountable".
DUP leader Arlene Foster and Sinn Féin vice president Michelle O'Neill indicated willingness over the weekend to resume negotiations after next month's general election.
"I think we are close to getting into position where we can get Stormont back up and running," Mr Smith said.
"These issues are important but what is really important are making sure that we deliver health services, that we deliver education and we deliver for people who are fed up of that institution not being up and running.
"I am confident with the best will, with a Christmas spirit, these parties can get this done."
He added that there is "no appetite" at Westminster for further legislation to extend the deadline to revive power-sharing at Stormont which has been collapsed for almost three years, since January 2017.
"The (British) Prime Minister (Boris Johnson) has been right behind these talks all along and will make a big push after this election," he said.
"I don't think taking powers back to London is the best way to proceed," Mr Smith added.
Conservative Party's commitment to Northern Ireland 'guaranteed'
The Conservative Party's commitment to Northern Ireland is "guaranteed" by the fact it is running General Election candidates there, chairman James Cleverly has said.
The Conservatives are the only one of the three cross-UK political parties to field candidates in the North.
Mr Cleverly said: "The promise we are making at this General Election is if the people here in Northern Ireland vote for our fantastic local Conservative and Unionist candidates, and if as a party we are able to get a stable working majority after this General Election, we will vote through this (Brexit) deal, we will leave by the end of January, we will refocus Parliament and we will refocus government on delivering on the international investment that is waiting to come into the UK."
"That we will invest in the National Health Service, we will invest in education, that we will invest in policing and business ... and we will do it for every single corner of the United Kingdom.
Pledges in the Northern Ireland Conservatives' manifesto include standing for a "modern unionism", getting Stormont back to work, backing the Brexit deal and modernising the Northern Ireland economy.
The Northern Ireland Conservatives are contesting four of the region's 18 constituencies at next month's General Election.
Gary Hynds, the party's deputy chairman in the region, will run as a candidate in Lagan Valley.
Matthew Robinson will stand in North Down, Grant Abraham in Strangford and Aaron Rankin in East Antrim.