Northern Ireland Secretary Owen Paterson has ruled out negotiating with dissident republicans until they commit to peaceful means.
Mr Paterson said the Government was "completely clear" that it could not talk to groups that were trying to wreak violence on innocent people.
But he also told BBC Radio 4's Today programme it was hard to identify who discussions should take place with, following a string of dissident bomb attacks.
His comments come after claims from Deputy First Minister Martin McGuinness that both the British and Irish Governments are involved in secret talks with violent dissidents. The claims have been denied by both administrations, and Mr Paterson told the programme: "Our position is completely clear and it's consistent with previous governments."
He added: "You cannot have meaningful talks, serious discussions, real negotiations - whatever you want to call them - with people who are not absolutely committed to peaceful means of pursuing their goals."
Asked if the Government was involved in "contacts", he went on: "We never discuss operational issues and the Today programme has been reporting on Northern Ireland long enough to know that.
"The problem we have is I don't think we are quite there yet. At the beginning of your question you mentioned the nature of these groups - they are small, they are fragmentary, they keep splitting and breaking and different people take over.
"It's not absolutely clear who you should be talking to, but the position of the Government is completely clear - we cannot talk to people who are still trying to kill 12-year-olds and two-year-olds, as they did last week."
Mr Paterson condemned the recent attacks as "disgusting" and insisted political violence would not succeed. Insisting authorities were not "complacent", he added: "There are a small number of very dangerous groups and we do not underestimate the threat they pose to the public."
Now that devolution has been completed, Westminster will work with local politicians to address long-term challenges. Asked to ensure that spending cuts would not harm Northern Ireland, Mr Paterson said: "We will stand by Northern Ireland. We will do what is necessary but this is a team effort."