The Taoiseach warned yesterday that only days remained to restore the initiative in the peace process before the Assembly election campaign began in earnest.
Mr Ahern said he was "not too sure" that renewed progress was possible and did not know the chances of success.
Speaking to journalists in Dublin, he also rejected criticisms made yesterday by the SDLP leader, Mr Mark Durkan.
Mr Ahern said he hoped all sides agreed that progress would have to be made very quickly.
"If not, my fear would be that it would be very hard to pull it back. We're into an election campaign and all the difficulties that brings," he said.
He added: "Obviously I'm talking to the British government. Obviously I'm talking to the parties directly concerned. We did a bit of that late last night and over the day. It's just too early to say if it's possible for us to construct something."
He said "everybody" in the process knew that Gen John de Chastelain would be restricted by an IRA confidentiality clause.
"Obviously people hoped that that could be presented in a way that would have been more expansive than was possible. So we have to explore what is possible, but it's difficult."
He had feared that the confidentiality clause would present difficulties. This was the reason he had assembled with his officials on Monday at 6.30 p.m. to contact Gen de Chastelain. However, the general could not be contacted.
Mr Ahern said it was not an option to postpone travelling to Hillsborough because contact could not be established overnight. "In actual fact, I was on the ground in Belfast walking across the Tarmac when it was pointed out to me that communications had been found again."
Mr Ahern said "everything we can possibly think of" was under examination to break the deadlock.
However, he repeated the belief that disclosure by the Irish or British governments of the quantities of arms, explosives and munitions put beyond use could jeopardise the IRA's commitment to continue its engagement with the decommissioning commission. "I do not know the mindset of the IRA to do that," he said. Republicans believed they had made "very substantial progress" in terms of what was sought from them.
"I think they would feel that the credit and the substantial nature of that is being lost in all of this. I don't agree with that."
On the complaints by Mr Durkan, Mr Ahern said no party had been excluded from the talks. "We've had more dialogue with Mark Durkan since September 1st than we've had with anybody else," he said.
"If he had been able to play a more constructive part on the decommissioning issue I would have been very anxious to have him in, but the circumstances just did not allow that."