Washington  - It was the campaign promise everyone was waiting to see fulfilled: Bo the First Dog finally joined US President Barack Obama and his family at the White House on Tuesday.

"I finally got a friend," Obama quipped as his daughter Malia paraded Bo before a swarm of press photographers and cameras on the White House lawn. "We are very pleased with Bo."

Bo had been a campaign promise to Obama's daughters Malia, 10, and Sasha, 7, which the president revealed to the world on the night of his November 4 election victory.

A six-month-old Portuguese water dog, Bo's arrival ends more than two months of heated speculation that rivalled many of Obama's more serious policy announcements.

Obama's wife Michelle joined the family in their first stroll with Bo outside the White House.

Bo is the first dog owned by any of the Obamas. Malia has allergies, which limited their choices to hypoallergenic breeds like the Portuguese water dog and the Labradoodle.