President Obama and first lady Michelle Obama paid a condolence call Sunday on the Biden family at the vice president’s residence at the Naval Observatory to express their sorrow about the death of Biden’s son, Beau, from brain cancer.

The president and his wife arrived at 1:42 p.m. and spent just under half an hour with the Bidens.

Out of respect for Biden’s family, the White House also canceled a reception for Ford’s Theatre that the president and first lady had planned to host at 4:30 p.m. Sunday in the Blue Room.

“Michelle and I are grieving tonight,” Obama said in a statement issued Saturday night. “Beau Biden was a friend of ours.  His beloved family – Hallie, Natalie, and Hunter – are friends of ours.  And Joe and Jill Biden are as good as friends get.”

Obama hailed Beau Biden for taking after his father. “He chased a life of public service, like his dad, serving in Iraq and as Delaware’s Attorney General.  Like his dad, Beau was a good, big-hearted, devoutly Catholic and deeply faithful man, who made a difference in the lives of all he touched – and he lives on in their hearts.”

White House aides have privately expressed wonder at and admiration for the vice president’s ability to carry out his duties without mentioning his son’s illness.

“Joe is one of the strongest men we’ve ever known,” Obama said in his statement. “He’s as strong as they come, and nothing matters to him more than family.”

The president also said:

“’I have believed the best of every man,’ wrote the poet William Butler Yeats, ‘And find that to believe it is enough to make a bad man show him at his best or even a good man swing his lantern higher.’  Beau Biden believed the best of us all.  For him, and for his family, we swing our lanterns higher."

The Senate opened its session Sunday afternoon with both the majority and minority leaders offering condolences to Vice President Biden and his family.

Sen. Mitch McConnell (R-Ky.) praised Beau Biden as a “dedicated public servant” and spoke warmly of his father.

“It’s hard to think of anything more important to him than his faith and his family,” McConnell said. “I hope he would find comfort in the former as he grieves such a terrible loss.”

Sen. Harry Reid (D-Nev.) described Beau as a “fine young man,” praising his time as an attorney general in Delaware and his military service.

“I’m sure his family will take solace knowing he lived a selfless noble life,” Reid said. He added these words to the vice president: “There’s a song, “Man of Constant sorrow,” and certainly it if applied to someone, it would be you, our friend, Joe Biden.”

Condolences also came in from the Bidens' home state of Delaware. Gov. Jack Markell (D), appearing Sunday on CNN's "State of the Union," called Beau Biden "an extraordinary human being" and "a great attorney general."

"But he was also just an incredibly good, real, genuine guy," Markell said. "And he was the most popular politician in the state. And he earned that. And he worked for it. And it's just an unbelievable loss."

Robert Samuels contributed to this report.