Sunday's massive march in Paris against terrorism drew dozens of world leaders in a show of unity - but not from from the United States, which was represented by its ambassador.
US Attorney General Eric Holder, who was in Paris on Sunday to attend a meeting of interior and justice ministers discussing measures to combat jihadist attacks, was meant to have participated in the rally according to the White House on Saturday, but did not do so, the US embassy in Paris confirmed.
The embassy did not say why Holder did not attend the march. It said the United States was represented in the huge rally by its new ambassador to France, Jane Hartley.
This screengrab from the White House website, that has been circulating on Twitter today, shows the president's schedule for Sunday wasn't exactly full.
Some observers questioned why the US presence was outranked by so many other countries in the demonstration, which also championed the principle of freedom of expression after Wednesday's massacre in Paris at the offices of the satirical weekly Charlie Hebdo.
And given the fact the US knows all too well the horrors of terrorism, many thought Obama would be there alongside the likes of Angela Merkel and David Cameron.
American media, meanwhile, was quick to slam Obama for his absence, with the New York Daily News screaming "You let the world down" on its front page. Political-insider magazine Politico wrote a story about the administration missing the rally under the headline: "Barack Obama's French kiss-off."
A CNN presenter, Jake Tapper, noted that Jordan, a close Muslim ally of the US, was represented by its king.
“I don't mean this as a criticism of the Obama administration, but as an American, I do wish that we were better represented in this beautiful procession of world leaders," Tapper was quoted as saying.
There was also some criticism for Obama on Twitter
And one reader of The Local France wrote an angry letter expressing his shame that the US head of state had not been in Paris.
In an impassioned letter titled “The Missing American President” Jack McNelly writes:
“I admire the strength and courage France has shown in the days following this tragedy. France is America's oldest ally. Without France, there is no United States.
“That being said, please understand I had little to nothing to do with my president not being present for the march in Paris with other world leaders this weekend. I am utterly embarrassed by his absence.
“The entire world is united with France in outrage and I have no idea why the leader of my country saw fit to not honor the event and the victims, with his presence.
"It seems my country asks so much from her allies and yet my president can't find the time to help hold the banner of freedom in France.
“I hope something of this magnitude will never happen again anywhere in the world, however if it does....count on me to be among the world citizens helping hold freedom's light. Je suis Charlie!"
Obama has expressed his outrage at the terror attacks in France.
“I want the people of France to know that the United States stands with you today, stands with you tomorrow,” said Obama before the march.
He also signed a book of condolence in the French embassy in Washington DC with the words "Vive la France".