WASHINGTON - Never mind that the calendar says it's March 19, around the West Wing and on Capitol Hill today, it's St Patrick's Day.

"We cherish this opportunity once a year to reaffirm the incredible bond between the United States and Ireland," President Obama told Irish Taoiseach Enda Kenny in an Oval Office meeting this morning. "This year it also gives us an excuse the stretch out St. Patrick's Day for a couple of extra days, which is always good. … Thank you for giving me an excuse to break out my green tie."

Beyond the obligatory talk of green and shamrocks, Obama praised Kenny for leadership during the tough times facing the Irish economy but noted that, on the topic of Northern Ireland, "there's a lot more work to be done before there's true unity of effort in that country."

Kenny, for his part, invited Obama to return to Ireland - recall that "O'bama" visited his distant relatives in Moneygall two years ago.

"And maybe the next time when our economies are moving in a more positive direction, we might actually have time to take out the sticks on the golf course," Kenny said.

Kenny and Obama weren't the only ones sporting the green ties.

Up on Capitol Hill, House Speaker John Boehner and many in the leadership put on their green for the annual Friends of Ireland lunch, where Obama, Kenny and others were treated to singing by Irish Tenor Anthony Kearns and a feast of rack of lamb, potatoes, sticky toffee pudding, glasses of Guinness and green clover-shaped cookies wrapped in plastic with a green ribbon.

Boehner toasted to Kenny and the U.S.-Irish relationship and joked: "I'd say this is the loudest gathering of Irishmen in Washington since the last time Joe Biden dined alone. It's like I'm always telling the president: You only tease the ones you love."

Then later, back at 1600 Pennsylvania, Obama and Kenny met again to hold the annual presentation of the shamrocks, this time in the East Room.

With a sprig of shamrocks neatly tucked in his suit coat pocket, Obama joked that things are going "green" at the White House in his second term.

"My new chief of staff is a McDonough; my National Security adviser is a Donilon; our new CIA director is Brennan; my new head speechwriter is a Keenan and Joe Biden has very kindly agreed to stay on as Irishman-in-chief," Obama said.

Biden couldn't attend because he was representing the United States at the installation of Pope Francis in Rome.

"For those of you who know Joe, literally the only thing that could keep him away from St Patrick's Day at the White House is the installation of a new pope," Obama said to laughter.

"In times of war and peace; good times and bad, Americans have always found a way to celebrate (Irish) heritage," he continued. "Even in times of trouble, if we're lucky enough to be Irish, even if it's only in spirit, then we are lucky enough and that's reason to give thanks.

"We look out for each other, we have each other's backs. And we recognize that no challenge is too great, no obstacle is too high if you've got a friend beside you and a nation behind you," he said. "That's been our history, that'll be our future."