Sinn Féin president Mr Gerry Adams and Ulster Unionist Party leader Mr David Trimble are to hold their fourth meeting in two weeks later today.
Sources confirmed the two leaders were to meet at Stormont as efforts continued to restore the devolved Assembly and power-sharing executive.
Mr Adams and Mr Trimble met on Tuesday but have declined to go into any detail about their recent contacts. However, Mr Adams yesterday portrayed the talks as part of a "network" of peace process meetings.
The west Belfast MP said his discussions with Mr Trimble were arguably the most important.
Nationalist SDLP Mr Mark Durkan today also travelled to London for a meeting with the prime minister's chief of staff, Mr Jonathan Powell, in Downing Street.
Mr Powell yesterday met the leader of the cross-community Alliance Party, Mr David Ford.
SDLP sources portrayed their meeting with Mr Powell as part of the continuing round of intense talks but said they would also be stressing the need for round-table discussion involving all sides.
The Taoiseach, Mr Ahern, said yesterday in the United States the time was running out for a deal to be completed in time to enable pre-Christmas Assembly elections.
PA