WASHINGTON -- President Barack Obama is sipping a Guinness at an Irish bar to observe St. Patrick's Day. At the White House, the main South Lawn Fountain is burbling green water.

Obama took his motorcade to the Dubliner Restaurant and Pub on a dazzling Saturday afternoon.

Wearing a moss green jacket pierced with a button that read, "VIP GUEST -- Tell 'em Danny sent you," Obama waded into a crowd wearing all manner of Kelly green waiting under a tent outside the tavern near Washington's landmark Union Station.

On Tuesday, Obama and Vice President Biden will meet Irish Prime Minister Enda Kenny and attend a St. Patrick's Day lunch at the Capitol. Then the president and first lady Michelle Obama will host an evening reception at the White House.