WASHINGTON (CBSDC) — The White House is going on the defensive for not sending any high-level administration officials to a unity rally in Paris on Sunday that was attended by several world leaders.

White House officials tell CBS News that the reason President Barack Obama didn’t go is because the president’s security would have significantly interfered with the crowd that was estimated at nearly 3.7 million people.

Attorney General Eric Holder, who was already in France for an anti-terrorism summit, did not attend. Secretary of State John Kerry was in India ahead of Obama’s upcoming trip. The only U.S. official to attend was the U.S. Ambassador to France Jane Hartley.

White House Press Secretary Josh Earnest told reporters Monday that they made an error not sending a higher profile official to the rally.

“I think it’s fair to say we should have sent someone with a higher profile to be there. That said, there is no doubt that the American people and this administration stand four-square behind our allies in France as they face down this threat and that was evident throughout last week,” Earnest said.

Earnest said that Obama would liked to have been at the rally if the circumstances had been different.

“The fact is this obviously — a march that the planning for which only begun Friday night and 36 hours later it had begun. What’s also clear is that the security requirements around a presidential-level visit or even a vice presidential-level visit are onerous and significant and in a situation like this they have a pretty significant impact on the other citizens who are trying to participate in a large public event like this,” Earnest said.

He continued: “We talk about this a lot when it comes to the president attending a basketball game, but the fact of the matter is there were not just thousands of people at the event, there were millions. It wasn’t just an arena that needed to be secured, but a large outdoor area that poses significant security challenges.”

Kerry told reporters in India Monday that he will be traveling to France this week.

“As soon as I heard about the plans for the march that took place yesterday, I asked my team to figure out what the earliest is that I could travel to Paris in order to show, once again, to reaffirm the connection between the United States and our oldest ally,” Kerry said. “And so, I will be traveling there on Thursday, and be there Friday, part of Friday. And I want to emphasize that the relationship with France is not about one day or one particular moment. It’s an ongoing, long-time relationship that is deeply, deeply based in the shared values, and particularly the commitment that we share in freedom of expression.”

The plans for the rally began Friday following terror attacks at French satirical magazine Charlie Hebdo and a Jewish Kosher market that left 17 people dead last week. The three terror suspects, Said and Cherif Kouachi and Amedy Coulibaly, were killed during raids.

German Chancellor Angela Merkel, British Prime Minister David Cameron, Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas were among dozens of world leaders who attended the Paris rally with French President Francois Hollande.

The administration was also criticized for not sending any officials to a rally in Washington, D.C., to coincide with the one in Paris.

Obama will be holding an international summit next month on how to prevent violent extremism.