Following talks with the Northern Ireland Secretary Paul Murphy at Stormont, the Upper Bann MP accused Sinn Féin leader Gerry Adams of "living in cloud-cuckoo-land" over the problems in the process.
The former Stormont First Minister, who lost his title when devolution was suspended last month, said: "I think it is important that we do bear in mind exactly what caused and triggered the present problem, and that was the activities of the Republican Movement.
"I must say, having listened to the comments made by Mr Adams after his meeting with the Secretary of State yesterday (Thursday) that republicans are living in cloud-cuckoo-land."
Mr Trimble referred to a raid by police on Sinn Féin's Stormont offices, conducted for evidence that the party operated a spy ring at the heart of the Northern Ireland Office.
Mr Adams on Thursday night insisted the main problem in the peace process was the failure of the British Government to honour its commitments under the Good Friday Agreement and he criticised the suspension of power-sharing.
Mr Murphy also met the nationalist SDLP, the cross-community Alliance Party, the UK Unionists and the Northern Ireland Unionists.
Alliance deputy leader Eileen Bell, after her meeting, called for a comprehensive review of the peace process and repeated calls for the IRA to stand down.
"It is democracy we are talking about not democracy with violence," the North Down MLA said.
"We want democracy plain and simple not the IRA helping them along the way."
Mrs Bell also signalled that, some time over the coming week, she expects the Northern Ireland Secretary to outline the process that could lead to the return of devolution.
She expressed reservations about an SDLP proposal that the Forum for Peace and Reconciliation in Dublin be reconvened to underpin support for the Good Friday Agreement.
The Forum was formed by former Taoisech Albert Reynolds after the 1994 IRA ceasefire to examine the constitutional future of a united Ireland.
The Forum sat for two years and involved nationalist parties in Northern Ireland, parties from the Irish Republic and Alliance.
SDLP leader Mark Durkan disagreed with Mrs Bell's claims that a reconvening of the Forum might be a distraction from efforts by the Northern Ireland parties to solve problems with the Good Friday Agreement and to restore power-sharing.