US mediation to resolve the Northern Ireland conflict has been discussed by President George W Bush and Sinn Fein president Gerry Adams.
Gerry Adams said he thanked President Bush for his interest.
The White House confirmed that Mr Bush spoke to Mr Adams on Sunday, following a call between Mr Bush and DUP leader Ian Paisley on Friday.
"I told him that we may need help at the White House to deliver" Sinn Fein's objectives, Mr Adams said.
Mr Adams is separately to meet NI's police chief in a ground-breaking move.
The Sinn Fein leader said he thanked President Bush "for his interest" and briefed him on the party's two objectives in the current negotiations.
"These are to get the DUP on board for an agreement and to ensure that the British Government's position remains faithful to the power sharing, equality-based and all-Ireland institutions contained in the Good Friday Agreement.
"I told him that we may need help at the White House to deliver these requirements."
White House spokesman Scott McClellan said the call was made as President Bush flew from his Texas ranch where he had been celebrating the Thanksgiving holiday.
He said the President had urged Mr Adams to provide leadership to advance the peace process and expressed support for the agreement proposed by Tony Blair and his Irish counterpart Bertie Ahern.
On Monday, while a Sinn Fein delegation meets the Prime Minister Tony Blair at Downing Street, Mr Adams will have his first meeting with the head of the Police Service of Northern Ireland, Hugh Orde.
A Sinn Fein spokesperson said "demilitarisation", the scaling down of security, would be discussed.
The party has consistently avoided meetings with the Chief Constable up until now.
The talks come as negotiations to break the deadlock in the peace process come to a head.
The British and Irish governments are pressing Sinn Fein and the DUP to agree to a new package of proposals by Tuesday.
Earlier on Sunday Mr Adams has said he believes the DUP is prepared to sign up to a deal to restore devolution.
Before signing up, Mr Paisley wants proof of IRA decommissioning.
Mr Adams said his party wanted to be "agents of change" but, like Mr Paisley, they also wanted a fair deal.
Speaking on the BBC's Breakfast with Frost programme on Sunday, Mr Adams said: "We can get an agreement, despite the refusal of Ian Paisley to talk."
Ian Paisley says his party will walk away if a deal is not right
Mr Adams said people were "hugely sceptical" that Mr Paisley would do a deal but added: "I think he will do a deal.
"But there is a responsibility on the British Government to press ahead with the Irish Government on all the outstanding aspects of the Agreement."
Later, Sinn Fein chairman Mitchel McLaughlin suggested the parties were "on the verge" of making a breakthrough.
"This has been a successful peace process - perhaps one that didn't develop as quickly as people on the ground would have hoped, but nonetheless it has been moving steadily in the right direction, despite all the hiccups and frustrations and disappointments.
"The final piece in bringing all-party dialogue about is this discourse between the DUP and Sinn Fein and I think we are on the verge of achieving that."
Mr Paisley is to meet the head of the decommissioning body to discuss the possibility of IRA disarmament on Monday, a move which has been welcomed by Sinn Fein.
The meeting with General John de Chastelain will come amid further talks to try to restore devolution to Northern Ireland.