In this handout provided by The White House, President Joe Biden and First Lady Jill Biden attend the wedding of Peter Neal and Naomi Biden Neal on the South Lawn of the White House on November 19, 2022 in Washington DC. Photo: VCG

US President Joe Biden welcomed guests to the White House Saturday for the wedding of his granddaughter Naomi - an unprecedented ceremony that was closed to the press.

The 28-year-old Washington-based lawyer married Peter Neal, 25, a law graduate, on the mansion's South Lawn in an 11 am ceremony witnessed by about 250 guests, according to the White House.

The grounds were suitingly decorated with white flowers, as invitees in rows looked on, according to photos taken from far away by AFP.

Naomi Biden is the daughter of the president's son Hunter.

"It has been a joy to watch Naomi grow, discover who she is, and carve out such an incredible life for herself," the president and First Lady Jill Biden said.

"Now, we are filled with pride to see her choose Peter as her husband and we're honored to welcome him to our family," they added. "We wish them days full of laughter and a love that grows deeper with every passing year."

It is not unheard of for the presidential mansion with the US' most stately address - 1600 Pennsylvania Avenue - to be decked out for nuptials.

The White House Historical Association says 18 weddings have been performed at the mansion, including those of Richard Nixon's daughter Tricia in 1971 and Barack Obama's official photographer, Pete Souza, in 2013.

The association says four times the White House has also hosted receptions for weddings held elsewhere, for instance that of George W. Bush's daughter Jenna in 2008.

But this is the first time a president's granddaughter is getting hitched there.

The White House in its brief statement said the Bidens hosted a wedding luncheon for family and the wedding party in the State Dining Room, and a reception with dancing was planned for later Saturday. But otherwise the president's office has given few details on this wedding, which is classified as strictly private and is closed to the press. 

"The White House press has covered weddings held there through history because the space belongs to the American people and a president's participation is an event of national interest," Kelly O'Donnell, an NBC reporter slated to become the next president of the White House Correspondents Association, said Thursday on Twitter.

AFP