WASHINGTON (REUTERS) - This time they got it right.

President Barack Obama and Chief Justice John Roberts, who flubbed the oath of office in a public inauguration ceremony four years ago, made it through without mistakes on Sunday at a private gathering that launched the Democrat's second term.

Shortly before noon on a sunny day, Mr Roberts, dressed in his traditional dark robe, strode into the oval-shaped White House Blue Room and positioned himself, with cue card in hand, at the edge of a light beam streaming in through the window.

Mr Obama, dressed in a suit, followed and planted himself opposite the chief justice. His wife, Michelle, and daughters Malia and Sasha, rounded out the tableau.

Mr Roberts asked Mr Obama to raise his right hand and repeat after him.

"I, Barack Hussein Obama, do solemnly swear," he began, using the president's full name. Mr Obama repeated the oath, with his left hand on a Bible, held by his smiling wife.

Mr Roberts, not wanting to repeat the mistake of 2009, looked down at his card and read most of its words, which Mr Obama repeated, promising to faithfully execute the office of president of the United States (US). Only at the end, including the final phrase "so help you God", did Mr Roberts keep his head up to maintain eye contact with the president.

After concluding the oath, the two men smiled and shook hands, visibly relieved. Mr Roberts congratulated the president and Mr Obama thanked him. The whole procedure lasted less than one minute. No mess-ups, no flubs.

"Good job, Dad," 11-year-old Sasha said.

"I did it," the president exclaimed.

The last time Mr Obama and Mr Roberts met at the White House for a swearing-in, the circumstances were different. Mr Roberts had mixed up his words when administering the oath at the ceremony in front of the Capitol, causing Mr Obama to do the same.

So the next day, they came together at the White House and did it again - without mistakes - in the Map Room. Only a handful of people were present, including four reporters.

The first lady and Mr Obama's daughters were not there.

Television cameras were prohibited and press photographers were not invited.

This year, the need for a private ceremony came from the constitutional requirement that the oath be taken on Jan 20.

Because that fell on a Sunday, the president did the official swearing-in at the White House and will repeat the procedure on Monday for a public celebration.

FAMILY MEMBERS ATTEND

Mrs Michelle Obama wore a deep blue dress by designer Reed Krakoff, according to a White House official. The girls wore stylish dresses as well, with Malia in blue and Sasha in fuchsia.

A small group of close family members watched from the side of the room, including the first lady's mother, Mrs Marian Robinson, brother Craig Robinson and his family. The president's half sisters Auma Obama and Maya Soetoro-Ng and her family also attended, along with close family friends "Mama Kaye" Wilson and Wellington Wilson.

The family was ushered into the Blue Room shortly before the ceremony began. Mr Roberts' wife, Jane, stood next to them.

The Blue Room was emptied of its traditional furniture, which had been moved to the large East Room instead.

A crystal chandelier hung from the ceiling from a chord that was wrapped in velvety-blue material, and the portraits of past presidents including John Adams, Thomas Jefferson and James Madison adorned the walls.

White House spokesman Jay Carney along with a handful of journalists and photographers made up the rest of the small group in attendance.