DUP leader Arlene Foster has warned Sinn Féin that the restoration of devolution is "no game".
Ms Foster blamed Sinn Féin for the continued lack of self-government in Northern Ireland more than two years after the powersharing institutions collapsed in January 2017.
Ms Foster made the comment while speaking to her party's spring conference in Omagh on Saturday.
It came less than 24 hours after the five local parties met the British and Irish governments to discuss the resumption of political talks to revive Stormont.
There has not been a functioning devolved government in Northern Ireland since January 2017 following a breakdown in relations between the DUP and Sinn Féin over a botched green energy scheme.
Numerous attempts at talks to resolve the impasse have been unsuccessful.
Following the talks on Friday, Sinn Féin president Mary Lou McDonald dismissed the efforts as a “sham”.
The Irish and British governments are expected to produce proposals to restart the talks process.
On Saturday, Ms Foster accused Sinn Féin of engaging in the “politics of ransom”.
“Two years ago Sinn Féin walked out of the Northern Ireland Executive. After the subsequent election in March 2017, Sinn Féin refused to enter the Executive or the Assembly until their shopping list of demands was ticked off,” she said, describing it as the “politics of ransom” and also “careless” pointing to how major decisions have been left to senior civil servants.
“The restoration of Stormont should not be about political brinkmanship or about party advantage. It should be about people.
“Whether it is contracts not being awarded, reforms not being implemented or new laws not being passed – be in no doubt our constituents are feeling the pain. It cannot go on.
“Four of the five parties in Northern Ireland are ready to move on and restore the Assembly.
“One party stands as the blockage.
“I warn Sinn Féin today from this platform: this is no game.
“Whatever your demands about the Irish language, they do not trump the genuine and heartfelt demands of the good people up and down this country.”
RHI scandal
Ms Foster also made reference to the Renewable Heat Incentive scandal which has seen her party face questions and criticism over the role of its ministers and special advisers.
The renewable health incentive scheme was set up in 2012 to boost uptake of eco-friendly heat systems.
But huge subsidies left taxpayers with a £490 million (€560m) bill.
An inquiry set up to examine what went wrong completed its public hearings last year, and is yet to publish its findings.
Mrs Foster said in the RHI inquiry hearings, there were “lessons for us all”.
“I have already apologised personally for mistakes on my part and corporately for mistakes made by the party,” she said.
“The way of doing business can – and must – be changed.
“We are committed to that, but Sinn Féin still hold out narrow party political demands.” – PA
