On Tuesday, President Trump, like others before him, will deliver the keynote address at a ceremony commemorating the Holocaust.

A president's participation in the Days of Remembrance ceremony, hosted by the U.S. Holocaust Memorial Museum, is not new; every president since the museum opened in 1993 has done so.

But unlike his predecessors, Trump — as a candidate and as president — has been widely criticized by Jewish organizations for what they see as a lackluster and slow response to the recent spike in anti-Semitic incidents across the country. His young administration also has been faulted for a couple of recent flubs about the Holocaust.

This means that the speech Trump will deliver during the week-long commemoration of the Holocaust could be a critical step for him to appease some of his critics.

Just a few months ago, on International Holocaust Remembrance Day, the president was criticized for a statement that failed to mention Jews and instead used a more general phrase, "innocent people."

"It is with a heavy heart and somber mind that we remember and honor the victims, survivors, heroes of the Holocaust," the statement said. "It is impossible to fully fathom the depravity and horror inflicted on innocent people by Nazi terror."

Afterward, Steven Goldstein, executive director of the Anne Frank Center for Mutual Respect and a frequent Trump critic, blasted the president: "How can you forget, Mr. President, that 6 million Jews were murdered because they were Jews? You chose the vague phrase, 'innocent people.' They were Jews, Mr. President."

And this month, White House press secretary Sean Spicer found himself apologizing profusely for another Holocaust blunder.

In trying to condemn Syrian President Bashar al-Assad's alleged use of chemical weapons, Spicer falsely said that Adolf Hitler "didn't even sink to using chemical weapons." Hitler gassed millions of Jews.

As the comment gained traction on social media, a reporter asked Spicer for clarification, but he only dug himself into a deeper hole. He said Hitler did not use sarin gas "on his own people the same way that Assad was doing."

Spicer apologized hours later, calling his statement "inappropriate and insensitive." He apologized again during a forum at the Newseum the next day, acknowledging that his gaffe was compounded by the fact that it occurred on the second day of Passover, the most celebrated of all Jewish holidays in the United States.

"I let the president down ... This was mine to own, mine to apologize for. Mine to ask forgiveness for," Spicer said.

Spicer's gaffe and his subsequent apologies rocketed around the Internet, even inspiring another satirical Spicer skit on Saturday Night Live.

It also prompted a statement from Goldstein, who called on Trump to fire his press secretary. He described Spicer's remarks as "the most offensive form of fake news imaginable." Goldstein also didn't appear moved by Spicer's multiple apologies, calling them "a bureaucratic response to an outcry."

The week-long Days of Remembrance began Sunday.

During Tuesday's ceremony at the Capitol Rotunda, a Holocaust survivor accompanied by a member of Congress will light six candles in memory of the victims, according to a news release from the museum. The annual observance will open with a procession of flags from each of the U.S. Army liberating divisions to commemorate the American troops who liberated the Nazi concentration camps.