New first lady Jill Biden took an unannounced detour to the US Capitol to deliver a basket of chocolate chip cookies to National Guard members, thanking them “for keeping me and my family safe” during President Joe Biden's inauguration.

“I just want to say thank you from President Biden and the whole, the entire Biden family,” she told a group of Guard members at the Capitol.

“The White House baked you some chocolate chip cookies," she said, before joking that she couldn't say she had baked them herself.

Joe Biden was sworn into office on Wednesday, exactly two weeks after Donald Trump supporters rioted at the Capitol in a futile attempt to keep Congress from certifying Biden as the winner of November's presidential election.

Extensive security measures were then taken for the inauguration, which went off without any major incidents.

Jill Biden told the group that her late son, Beau, was a Delaware Army National Guard member who spent a year deployed in Iraq in 2008-09. Beau Biden died of brain cancer in 2015 at the age of 46.

“So I'm a National Guard mom,” she said, adding that the basket was a “small thank you” for leaving their home states and coming to the nation's capital.

President Biden offered his thanks to the chief of the National Guard Bureau in a phone call Friday.

“I truly appreciate all that you do,” the first lady said.

“The National Guard will always hold a special place in the heart of all the Bidens.”

Jill Biden's unannounced troop visit came after her first public outing as first lady.

She highlighted services for cancer patients at Whitman-Walker Health, a Washington institution with a history of serving HIV/AIDS patients and the LGBTQ community.

The clinic receives federal money to help provide primary care services in underserved areas.

Staff told the first lady that cancer screenings had fallen since last March because patients didn't want to come in because of the coronavirus pandemic.

More and more patients are taking advantage of options to see a doctor online.

When the issue of universal access to broadband internet was raised, Jill Biden, who is a teacher, said she hears from teachers around the country who can't get in touch with their students because of the spotty access in some areas.

“We just have to work together and address some of these things," she said.

“The first thing we have to do is address this pandemic and get everybody vaccinated and back to work and back to their schools and get things back to the new normal.”