US President Donald Trump and first lady Melania took part in the Veterans Day observance at Arlington National Cemetery on Wednesday.
The annual presidential rite was their first public appearance since Mr Trump's failed re-election bid.
President-elect Joe Biden and his wife Jill attended a Veterans Day event in Philadelphia at the Korean War memorial.
Mr Biden’s son Beau was a major in the Delaware Army National Guard and died in 2015 of brain cancer.
During the presidential election campaign, he often spoke emotionally of his son’s service.
Ms Biden made military spouses and families one of her signature issues when Mr Biden was Barack Obama’s vice president, and aides said it might be one of her focal points as first lady.
After the public ceremony, Mr Biden spent time in private briefings with his transition team.
Meanwhile, Mr Trump has spent the past several days holed up at the White House tweeting angry, baseless claims of voter fraud in battleground states after his election loss.
He has made no public comments since Mr Biden on Saturday passed the 270 electoral votes needed to win the presidency.
Although his official schedule has been empty of public events, Mr Trump has made several personnel moves.
He fired his defence secretary Mark Esper and installed three staunch loyalists to top defence jobs.
Meanwhile, his legal team has filed a barrage of lawsuits alleging fraud in the battleground states.
In Georgia, Secretary of State Brad Raffensperger announced an audit of election results that will start a full hand recount.
Mr Biden leads Mr Trump by about 14,000 votes of nearly 5 million counted in the state.
But even if Georgia were to go in Mr Trump's favour, it would not be enough for him to win the White House.
The president’s resistance to acknowledging the outcome of the race has stalled the transition process.
The head of the General Services Administration, who Mr Trump appointed, has held off on certifying Mr Biden as the winner.
The certification frees up money for the transition and clears the way for Mr Biden’s team to begin putting in place the process at agencies.
“I just think it’s an embarrassment, quite frankly,” Mr Biden said of Mr Trump’s refusal to concede.
With the exception of weekend visits to his private golf club in northern Virginia, Mr Trump has remained at the White House since election day and last appeared before cameras to deliver a statement six days ago.
He was joined by Vice President Mike Pence and his wife, Karen.
Mr Pence had been scheduled to travel to Sanibel, Florida, from Tuesday to Saturday, the Federal Aviation Administration said.
But he will instead be in Washington on Wednesday. Mr Pence’s office did not immediately comment on the status of his trip.
