(CNN) President Donald Trump spoke out Tuesday against a series of recent threats against Jewish Community Centers and other Jewish institutions, but advocacy groups and political opponents said his remarks did not go far enough and are now urging a more robust federal response.

The Anne Frank Center for Mutual Respect delivered a searing statement late Tuesday morning, accusing the White House of tacitly embracing anti-Semitism with its earlier silence and for failing to specifically cite the Jewish people in its International Holocaust Remembrance Day statement last month.

"The President's sudden acknowledgment is a Band-Aid on the cancer of anti-Semitism that has infected his own administration," the group's executive director, Steven Goldstein, said in a social media post. "(Trump's) statement today is a pathetic asterisk of condescension after weeks in which he and his staff have committed grotesque acts and omissions reflecting anti-Semitism, yet day after day have refused to apologize and correct the record."

The statement continued: "Make no mistake: The anti-Semitism coming out of this administration is the worst we have ever seen from any administration. The White House repeatedly refused to mention Jews in its Holocaust remembrance, and had the audacity to take offense when the world pointed out the ramifications of Holocaust denial."

Trump's comment on Tuesday, delivered after a tour of the National Museum of African American Museum and Culture in Washington, followed bomb threats made against 11 Jewish Community Centers on Monday.

"The anti-Semitic threats targeting our Jewish community and community centers are horrible and are painful and a very sad reminder of the work that still must be done to root out hate and prejudice and evil," Trump said.

The JCC Association of North America said there have now been 69 threats made against 54 locations in 27 states and one Canadian province since early January. In St. Louis, officials at a Jewish cemetery reported on Monday that more than 100 grave sites had been vandalized in the previous week.

The White House denounced the threats Monday evening in a statement.

"Hatred and hate-motivated violence of any kind have no place in a country founded on the promise of individual freedom. The President has made it abundantly clear that these actions are unacceptable," said deputy press secretary Lindsay Walters.

And Ivanka Trump, a convert to Judaism, responded as well Monday night, tweeting that "America is a nation built on the principle of religious tolerance. We must protect our houses of worship & religious centers. #JCC"

America is a nation built on the principle of religious tolerance. We must protect our houses of worship & religious centers. #JCC — Ivanka Trump (@IvankaTrump) February 20, 2017

Questioned about the Anne Frank Center's criticism, White House Press Secretary Sean Spicer told reporters that he had seen the statement.

"I wish that they had praised the President for his leadership in this area, and I think that hopefully, as time continues to go by, they recognize his commitment to civil rights, to voting rights, to equality for all Americans," he said.

Trump, he added, has been "very forceful in his denunciation" of bigotry.

Pushing for further action

But leading Jewish groups want the administration to do more.

"The president is not just an elected official who administers the country," said Anti-Defamation League CEO Jonathan Greenblatt. "He sets the tone for the nation. And we look to our presidents to do more than just sign bills — we look to them for moral leadership."

Greenblatt suggested that the tone of the presidential campaign had emboldened extremists, noting that the proportion of Americans who hold anti-Semitic attitudes -- about 14%, according to ADL polling -- has remained mostly constant over the past two decades.

"The failure of our elected officials, the failure of political leadership, the failure of our leadership, the failure of our public leaders to step up and say 'enough,' has created a vacuum that extremists have exploited," he said. "And when abuse is allowed, because it's not forthrightly condemned, you see that it spreads like a virus."

On Tuesday, the Simon Wiesenthal Center, a Jewish human rights group, sent a letter to Attorney General Jeff Sessions asking that the Justice Department launch a task force "with the assignment of identifying and capturing the culprit or culprits who seek to terrorize American Jewry through their threats."

The FBI addressed the issue last week, saying in a statement that it was "investigating possible civil rights violations in connection with threats to Jewish Community Centers across the country" and described the matter as an "ongoing" concern.

A spokesman from the Southern Poverty Law Center, which has been critical of Trump and his close relationship with top White House strategist Steve Bannon , who headed the alt-right nest of Breitbart before joining Trump's campaign last year, said Tuesday's statement showed the President "slowly edging toward the point where he needs to be."

"There is no policy prescription that has been discovered to quell or slow, or even eradicate, age-old ideas (like anti-Semitism)," Ryan Lenz, editor of the SPLC's Hatewatch blog, told CNN. He blamed the Trump campaign for boosting those voices by not taking an immediate, proactive stand against them.

"Now what we're seeing right is the aftermath -- the echo to that moment -- which is that the ideas have firmly rooted themselves and found a place in the mainstream," Lenz said. "It's hard to put the genie back in the bottle once you get to this point."

Message delivered?

Hillary Clinton joined the chorus early Tuesday, calling on Trump to take a more vocal role.

"JCC threats, cemetery desecration & online attacks are so troubling & they need to be stopped," the former Democratic presidential candidate said in a tweet. "Everyone must speak out, starting w/ @POTUS."

JCC threats, cemetery desecration & online attacks are so troubling & they need to be stopped. Everyone must speak out, starting w/ @POTUS. — Hillary Clinton (@HillaryClinton) February 21, 2017

House Speaker Paul Ryan weighed in after Trump's remarks, tweeting, "Anti-Semitism in any form is abhorrent, and I encourage authorities nationwide to take these threats seriously."

Anti-Semitism in any form is abhorrent, and I encourage authorities nationwide to take these threats seriously. — Paul Ryan (@SpeakerRyan) February 21, 2017

Trump has been presented with opportunities to denounce the threats before. During a lengthy news conference last week, a reporter from an Orthodox Jewish weekly based in New York tried to ask about "an uptick in anti-Semitism and how the government is planning to take care of it."

But Trump cut him off, calling the question unfair and declaring in response, "I am the least anti-Semitic person that you've ever seen in your entire life. No. 2, racism, the least racist person."

JUST WATCHED Trump: I am the least anti-Semitic person Replay More Videos ... MUST WATCH Trump: I am the least anti-Semitic person 01:44

When the reporter tried to explain he did not mean to impugn Trump personally, he was told, "quiet, quiet." It was the second straight day that the President, who had held a joint press conference with Israeli PM Benjamin Netanyahu 24 hours earlier, had not directly addressed a question about anti-Semitism.

"This is both worrisome and puzzling," American Jewish Committee CEO David Harris said in a statement last week, asking that the Jewish community's concerns not be dismissed or scorned by the administration as political attacks.

"That's why the questions are being asked at press conferences, and not in order to cast aspersions on your administration," he added. "But if every such question elicits either no substantive response or, mistakenly, is taken personally, then what are people of good will supposed to conclude?"