US President Joe Biden on Saturday commended Americans for their strength and resilience in the face of the raging Covid-19 pandemic, urging "hope and renewal" during the holiday season.

In his first Christmas address as president, Biden praised "the enormous courage, character, resilience, and resolve in all of you who heal, comfort, teach, and protect and serve in ways big and small."

"You show there is much to gain in appreciation and gratitude for the gift of time and goodwill we share as we look out for one another," Biden said in a statement with First Lady Jill Biden.

US President Joe Biden visits the Christmas Tree in honor of First Lady Jill Biden in Washington, DC, on December 24, 2021
US President Joe Biden visits the Christmas Tree in honor of First Lady Jill Biden in Washington, DC, on December 24, 2021 AFP / Nicholas Kamm

"Again and again, you show how our differences are precious and our similarities infinite."

Biden, a devout Catholic, went on, saying that "for the nation, we pray for the promise found in Scripture -- of finding light in the darkness, which is also perhaps the most American of things to do."

Later Saturday, the Bidens spoke to service members stationed domestically and at US bases overseas. Also present at the event was the newest addition to the first family, a German shepherd puppy named Commander.

"As your commander in chief, I wanted to take this opportunity to say thank you, thank you, thank you," Biden told soldiers based in Qatar, Bahrain, Romania and the US state of Colorado.

US President Joe Biden and US First Lady Jill Biden, with their new dog Commander, speak virtually with military service members
US President Joe Biden and US First Lady Jill Biden, with their new dog Commander, speak virtually with military service members AFP / SAUL LOEB

"You are the solid steel spine of the nation," he said, recalling that his son Beau, who died of brain cancer in 2015, had served in Iraq.

"Jill and I know how hard it is for you" to spend a season of togetherness away from loved ones, he added.

"It's a poor substitute for what you are missing," Biden said of his presidential message.

Jill Biden, meanwhile, spoke about her father who served in the US Navy during World War II.

With Americans battered by the deadly pandemic and economic hardship exacerbated by record-high inflation, the presidential couple have focused on end-of-year traditions -- pardoning a turkey on Thanksgiving and decorating the White House for Christmas -- to send messages of hope and joy.

But with the country rocked by deep political divisions, even a Christmas Eve greeting turned sour for Biden Friday, when a man to whom he was wishing a merry Christmas during a video call from the White House, launched at him with an insult that is popular among supporters of Biden's predecessor Donald Trump.