Washington  - US President Barack Obama praised the people of Northern Ireland for rejecting violence and standing up for peace against "those who would seek to destroy it."

Obama spoke at a White House ceremony Tuesday to celebrate Saint Patrick's Day with the traditional visit by the Irish prime minister, Brian Cowen.

The meeting comes as authorities in Northern Ireland continue to investigate the murders of two British soldiers and a policeman by an extremist splinter group associated with the now disbanded Irish Republican Army (IRA).

The people of Northern Ireland and their leaders have "shown they judge progress by what you build, and not what you tear down, and they know that the future is too important to cede to those who are mired in the past," Obama said.

Cowen is among a larger contingent of Irish and Northern Irish officials in Washington Tuesday. US Secretary of State Hillary Rodham Clinton strongly condemned the recent violence during a meeting with Irish Foreign Minister Michael Martin Monday.

On Tuesday, Clinton met with Sein Fein leader Gerry Adams and later was to meet with Shaun Woodward, the secretary of state for Northern Ireland, and Peter Robinson and Martin McGuinness, the first minister and deputy first minister of Northern Ireland, respectively.

Obama, who like Cowen wore a green tie, spoke of America's deep historical ties to Ireland as the two leaders spoke to the press. Cowen fulfilled a long standing tradition by presenting Obama with a bowl of shamrocks.

Outside, the White House fountain had been dyed green for the day's celebrations.

"The contributions of the Irish to the American story cannot be overstated," Obama said. "Irish signatures are on our founding documents. Irish blood's been spilled on our battlefields."

Also, Obama nominated Daniel Rooney, the owner of American football champion Pittsburgh Steelers, as the next ambassador to Ireland. Rooney, 76, has played a long role in the Irish-American community.

Rooney through charitable groups supported the Irish peace process and co-founded the American Ireland Fund in 1976, which has raised more than 300 million dollars for peace and education programs in Ireland.

Rooney, a lifelong Republican, endorsed Obama during the campaign. His Steelers have won six Super Bowl titles, more than any other team in the National Football League. (dpa)