The government's 26 March deadline for devolution to be restored to Northern Ireland will not be changed, Secretary of State Peter Hain has again said.
Peter Hain issued a warning to the parties
Mr Hain was speaking ahead of a meeting with Irish Foreign Minister Dermot Ahern at Hillsborough Castle.
Mr Hain said if there was no deal he would implement the new water charges.
However, if a power sharing executive wanted to follow a different policy, the government could help them with that financially, he said.
Speaking about the deadline, Mr Hain said: "The St Andrews legislation leaves absolutely no discretion for me, even if I wanted to display that discretion, to do anything other than restore or dissolve the assembly.
"The prime minister's official spokesman today confirmed that the prime minister was absolutely clear that there would be no other available choice for the parties.
"The prime minister himself made that clear last week."
He also said if the parties wanted to see water charges changed then it was up to them.
"The policy will remain unchanged on water charges and on rates if I remain as secretary of state in charge of these matters," Mr Hain said.
"If the parties take responsibility for these matters then they can determine the policy and I think we might be able to help them determine the policy depending on whether they are serious about restoration or not."
Mr Ahern said the Irish government was willing to contribute to a financial package if it was to the mutual benefit of people on both sides of the border.
The comments came after assembly members, elected on 7 March, arrived at Stormont to pick up their office keys.
Meanwhile, Treasury officials will travel to Northern Ireland to meet the parties for talks on a possible financial package for the new executive.
Mr Hain met with Sinn Fein, the Ulster Unionists and Alliance on Monday and will meet with the DUP and Sinn Fein on Tuesday.
After meeting the secretary of state, Sinn Fein President Gerry Adams said he wanted water charges to be abolished as party of any economic peace dividend.
Mr Adams said the parties stood a chance of making progress in these matters if they could convince the Treasury they were ready to take their places in a new power sharing executive.
The 108 MLAs will sign the assembly roll on Tuesday.
If a power-sharing executive is formed it will have four DUP ministers, three Sinn Fein, two UUP and one SDLP.
The Northern Ireland Assembly has been suspended since October 2002, amid allegations of an IRA spy ring at Stormont. A subsequent court case collapsed. Direct rule has been in place since that date.