A Northern Ireland Office spokeswoman said: "This was a useful exchange. The secretary of state listened to Mr Trimble's views on the seriousness of the situation."

John Reid: Asked to assess IRA ceasefire

Sources close to Mr Trimble said he had pressed Dr Reid on the status of the IRA ceasefire.

"He specifically pressed Dr Reid to define what he regards as a ceasefire," said the source.

"He wanted to know if it was okay to train terrorists in Colombia so long as police and soldiers are not getting shot in Northern Ireland."

'Undisputed facts'

Speaking before the meeting, Mr Trimble said he would be forced to take action if the government allowed the political process to drift into crisis.

"There is plenty of evidence linking Irish republicans with paramilitary activity by FARC - that is clear," he said.

"It is also quite clear that leading members of the IRA and Sinn Fein were in FARC-controlled territory - these are undisputed facts.

"We do not yet have evidence in terms of Castlereagh, but it has reached the point that the acting chief constable formally informed the Policing Board of the police's view on the matter."

Earlier, SDLP leader and Deputy First Minister Mark Durkan said he believed the IRA was "still active".

Mr Durkan was speaking after meeting Sinn Fein President Gerry Adams at Stormont on Tuesday as the political row continued over the status of the IRA ceasefire.

"The fact is the IRA remains active," said Mr Durkan.

"They have always remained active and we know that the issue is recently there have been a number of events that have given concern that the IRA was involved either directly or indirectly."

Motion

However, he also said there was also a credibility problem with the intelligence services.

However, Mr Adams again maintained that the IRA ceasefire was intact, and said people should focus on other issues.

David Trimble: Wants clarification on status of IRA ceasefire

On Monday night, Mr Trimble held talks with Irish Prime Minister Bertie Ahern after an Ulster Unionist motion over alleged IRA activity failed to win support in the Northern Ireland Assembly.

Speaking after the meeting Mr Ahern said that he believed the IRA ceasefire was "very much in place".

Last October, Dr Reid said the government no longer recognised the ceasefires of the UDA/UFF - the largest loyalist paramilitary organisation - and the smaller, splinter group, the Loyalist Volunteer Force.

It followed the murder of a County Armagh journalist and an upsurge in street violence.