Tuesday's official announcement comes the day after Catholic and Protestant leaders reached an agreement enabling Prime Minister Tony Blair to call fresh elections for the British province's suspended assembly.
Northern Irish voters should have gone to the polls in May, but the election was cancelled by Britain. The government in London judged pledges from the Irish Republican Army to end all violence were not sufficient to ensure the stability of a post-election government.
“Yes, we have a deal” on restoring Northern Ireland's power-sharing institutions, a source close to the Protestant unionist leadership told AFP Monday night.
“There is agreement on how this is going to work its way out,” said a source close to Sinn Fein - the political wing of the Irish Republican Army (IRA), the largest Roman Catholic paramilitary organisation.
David Trimble, head of the Ulster Unionist Party (UUP), held a number of meeting with Sinn Fein’s Gerry Adams during the day.
Blair and Irish Prime Minister Bertie Ahern are due to meet at Hillsborough, near Belfast, on Tuesday to announce details of the election deal.
“There is agreement on how this is going to work its way out”
Unidentified source close to
The deal is believed to include a third act of decommissioning by the IRA.
Northern Ireland's devolved administration was suspended a year ago after charges the IRA were gathering intelligence in the assembly.
A statement issued by the UK government on Monday said that Mr Blair “stands ready to do whatever is necessary” to aid the Northern Ireland political process.
Sinn Fein described the discussions as being at a very sensitive stage.
Despite the fact that Blair cancelled a number of engagements on Monday as he recovered from the medical treatment he received at the weekend for an irregular heartbeat, a Downing Street spokesman said the prime minister stood ready to do whatever was necessary.
Both Blair (R) and Bush (L) have
urged rival parties to cooperate
Negotiators from the UUP and Sinn Fein held talks lasting more than 12 hours at Hillsborough Castle on Sunday.
The unionists are demanding a significant shift by republicans to indicate that all IRA activity is ended.
Trimble said an inclusive administration could not operate unless republicans made it clear they were going to operate exclusively by peaceful and democratic means.
“If they cannot do that, then the prime minister has a very stark choice: no inclusive Assembly, no inclusive executive - what then? - if he's going to have elections, he's going to have to answer that question,” he said, according to the BBC.
Trimble added, however, that political progress in Northern Ireland could proceed without IRA decommissioning being completed immediately.