The DUP has said "huge differences" still remain to be resolved before powersharing at Stormont can be restored.
Northern Ireland's five main political parties met for the first of a series of round-table crisis talks on Monday afternoon in a bid to find a way to end the year-long political stalemate.
Following the meeting, which lasted little over an hour, the DUP's Simon Hamilton said: "We have huge differences between the parties on a range of key issues and we have been working through those issues.
"We have made some progress on many but there are some big and, in some cases, quite significant gaps."
He added: "We want to get this assembly back up and running again. We want to do that on the basis of accommodation that is fair, one that allows a sustainable Stormont to be restored."
Sinn Fein senior negotiator Conor Murphy said: "This process will come to an end in the next short while and we will make a judgement then as to whether a deal is possible or not."
The Newry and Armagh Assembly member added: "We entered in to what we were told and agreed was a short and sharp process to see was an agreement possible.
"We were told this is the last chance and we accept that the talks cannot go on forever.
The UK Government agreed that difficult issues remain to be resolved but insisted that "progress has been made" and an agreement is "achievable."
In a statement a spokesperson said: "Good progress has been made in discussions during this latest phase of talks but some difficult issues remain.
"Our assessment is that an agreement in the coming days, while not certain, is achievable.
"Time remains short. We all need to focus our collective efforts in the coming days on working together to form an Executive.
"The Secretary of State will provide an update to Parliament on Wednesday."
Ulster Unionist MLA Steve Aiken said there had been "no progress at all".
He said: "Today we have a situation where we are being asked to give them even more time and we are not being given the opportunity to discover what the DUP and SF have been working towards."
Alliance Party leader Naomi Long warned: "There is an opportunity still for a deal to be done, but at the moment I do not think we could have any confidence that a deal could be done if the process continues as it has."
The SDLP's Nichola Mallon added: "What we got today was more of the same."
Northern Ireland has been without a powersharing government for a year, after the powersharing coalition led by the Democratic Unionist Party (DUP) and Sinn Fein collapsed.
Discussions began in January in a bid to break the impasse at Stormont and restore the executive.
UK Secretary of State Karen Bradley is due to update the House of Commons on progress later this week.