Theresa Villiers has said there will be no extra money to help Northern Ireland resolve its budget dispute.
She reiterated calls for politicians to implement the Stormont House Agreement and said the prospect of the first minister or deputy first minister resigning and a cycle of assembly elections should be avoided.
Ms Villiers was giving evidence to the Northern Ireland Affairs Committee of MPs at Westminster.
She said: "We won't be giving additional money to Northern Ireland on top of the £2 billion or so in extra spending power which comes with the Stormont House Agreement.
"That is still very much on the table, we hope the Agreement will ultimately be deliverable in which case the financial package comes with it.
"We are not going to top up that financial package, we don't think it would be right to fund a more expensive welfare system for Northern Ireland than the rest of the UK."
The Agreement was signed between the five main Northern Ireland parties in December, and Prime Minister David Cameron said extra financial "firepower" had been agreed for the devolved administration. It subsequently emerged much of that involved extra flexibility around loans as well as offers to fund a civil service redundancy scheme criticised by trade unions but supported by ministers.
The Treasury has promised to provide £500 million to fund shared and integrated education projects over the next 10 years, as well as £350 million in loans for other infrastructure schemes over the next four years.
Sinn Fein is seeking an additional £1.5 billion for Northern Ireland. That equates to the amount of spending power Stormont power-sharing ministers have lost over the course of the last parliament, the party said.
It is refusing to implement welfare reforms ordered by the Conservative Government over fears "austerity" would hurt the most vulnerable.
Ms Villiers said: "If we duck the need to get our finances in balance we can see from examples around Europe of what happens - governments which cannot get their spending under control end up triggering the economic chaos we have seen in Greece - and that is extremely negative for the vulnerable people that we want to protect."
She said she wanted to create a moral and humane system.
"The consequences are not felt by the wealthy, they are felt by people who lose their jobs and who have to cope with chaos in public services as a result of deteriorating public services.
"I think there is a moral case for a government and a nation living within its means and to do that it has to mean tackling the welfare bill, it has got out of control.
"It is possible to provide a humane system which supports the vulnerable but also encourages work because the best way to tackle poverty is to get people into work."
SDLP leader Dr Alasdair McDonnell said in some cases work did not exist for people to go to and called for a "prosperity process" saying his party was not opposed to the Stormont House Agreement, only details of it.
The Executive is expected to run out of money within months unless a deal is struck on welfare reform, ministers have predicted.
Meanwhile Foreign Affairs Minister Charlie Flanagan said "serial brinkmanship" must be replaced by generous, courageous and effective partnership government in Belfast.
He was speaking during Dail statements on Northern Ireland.
"For months, Northern Ireland has been mired in deadlock over the budgetary and financial commitments agreed at Stormont House," he said.
"These are fundamentally important issues that get to the heart of governance and I understand how challenging it is to find the necessary compromises.
"But in Government there are always constraints; there are always difficult choices to be made within limited resources.
"A much more creative and constructive approach than has so far been evident is needed to overcome the current impasse on these issues.
"Instead, what we have seen over the past few months is serial brinkmanship."
He said last-minute negotiations in the spotlight of another feigned crisis was not leadership.
"It damages people's faith in the institutions meant to serve them, undermines power-sharing politics and, as the Taoiseach stated, ultimately risks political collapse," he added.
"We cannot afford, and cannot allow, that level of political neglect."
