US President George W Bush marked a St Patrick's Day overshadowed by recent setbacks in the peace process by pledging to help the Irish people move toward a lasting agreement.
Before he met the McCartney sisters, who are campaigning for justice for their brother who was murdered in Belfast, the president said: "As you work for peace, our government and the American people will stand with you."
President Bush was presented with a traditional bowl of shamrock from the Taoiseach Bertie Ahern.
U.S. President George W. Bush receives a bowl of Shamrocks as a St. Patrick's Day gift from Irish Prime Minister Bertie Ahern, in the Roosevelt Room of the White House, today
Mr Ahern said the Belfast Agreement has improved the political landscape in the North, but more work needs to be done to achieve lasting peace.
"Recent events have damaged confidence, but they have also crystallised what must now be done to finalise the process and achieve stable partnership governments in Northern Ireland," Mr Ahern said.
President Bush praised the courage of the McCartney sisters at the reception in the White House. He said the women have "committed themselves to a peaceful solution, and hopefully their loved one will not have died in vain."
The sisters - Catherine, Gemma, Claire, Paula and Donna - also got support from several senators during a visit to the Capitol building on Wednesday. Among them was Senator Ted Kennedy, who has met with Gerry Adams every St Patrick's Day for the last seven years but is refusing to see him this year.
"No political party can also have an armed unit that continues the violence and criminality in today's world," Senator Kennedy said.