Washington (CNN) The heads of Great Britain, Germany and Israel were there.

But President Barack Obama didn't attend a unity march in Paris on Sunday, days after the deadly attack on the satirical newspaper Charlie Hebdo. Nor did his secretary of state, John Kerry, who has deep ties to France.

Kerry was in India, attending an entrepreneurship summit with new Prime Minister Narendra Modi -- with whom the United States is hoping to develop much closer trade ties.

Instead, the United States was represented by U.S. Ambassador to France Jane Hartley.

Attorney General Eric Holder was also in Paris, attending a security summit on combating terrorism. He recorded interviews that appeared on several U.S. news outlets Sunday, but was not spotted at the unity march.

No one from the administration would speak on record about the U.S. representation at the march.

"Attorney General Holder -- a Cabinet level official -- is representing the United States at the security meetings in Paris today. He is joined by the DHS Deputy Secretary [Alejandro] Mayorkas. The United States is represented at the march by Ambassador Hartley," a senior Obama administration official said.

An administration official added: "As far as public signs of French solidarity from the U.S. -- don't forget several public statements from the President, his call to [French President Francois] Hollande and a condolence stop to the French embassy."

Beyond that, the official said "all relevant components" of the U.S. government have been aiding their French counterparts, in some cases on "essentially a minute-by-minute basis to support their efforts."

On Sunday night, a White House official who also asked not to be named added: "It is worth noting that the security requirements for both the President and (Vice President) can be distracting from events like this - for once this event is not about us!" The official did not address how other prominent world leaders were able to work around the security requirements.

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Hundreds of thousands of people attended the march in Paris on Sunday, waving both French flags and those of other nations.

British Prime Minister David Cameron, Israeli Prime Minister Benjamin Netanyahu, German Chancellor Angela Merkel, Palestinian Authority President Mahmoud Abbas and Russian Foreign Minister Sergey Lavrov were among those who attended, along with religious leaders.

Speaking on air with CNN's Jake Tapper, who was at the rally, "Global Public Square" host Fareed Zakaria called the absence of top officials a mistake.

France is the United States' "deepest ideological ally," he said, and it would have been a meaningful image to have a senior administration member, or the President, standing shoulder to shoulder with other leaders.

Zakaria noted that security concerns didn't dissuade Netanyahu or Abbas or other leaders from showing up. But Obama's absence did show that the struggle against radical Islam is "not all about America," he said.

"Many people have tended to think that Islamic terrorism wouldn't exist without America," Zakaria said. "This is really a struggle between the civilized world and a band of extremists. Even if you take the U.S. out of it ... the civilized world is up in arms."

Obama commented on the Paris attacks Friday in Tennessee, saying he wants the people of France to know the United States "stands with you today, stands with you tomorrow."

The White House also announced Sunday that it will host a Feb. 18 summit aimed at countering violent extremism.

White House Press Secretary Josh Earnest said that event will "highlight domestic and international efforts to prevent violent extremists and their supporters from radicalizing, recruiting or inspiring individuals or groups in the United States and abroad to commit acts of violence, efforts made even more imperative in light of recent, tragic attacks in Ottawa, Sydney and Paris."

He said the summit will include presentations, panel discussions and small group meetings, focused on the local, state and federal government levels.