After what may have been the worst day in Sean Spicer's PR career as White House press secretary, when he first suggested Adolf Hitler was better than Syria's Assad because he did not use chemical gas, then quickly followed up by saying that Trump was seeking to "destabilize" the Middle East, on Wednesday Spicer said he let President Trump down, and apologized for his comments.

Spicer said his remark, which he said was meant to shame Syrian leader Bashar Assad for a deadly gas attack, distracted from Trump’s decision to respond with a cruise missile strike and his successful meeting with Chinese President Xi Jinping.

"I made a mistake. There's no other way to say it. I got into a topic that I shouldn't have and I screwed up," Spicer said during an event at a museum in Washington. "I hope I showed that I understand that I did that and that sought people's forgiveness because I screwed up."

He admitted that “there’s no comparing atrocities” and said that “I’ve let the President down.”

“Your job as a spokesperson is to help amplify the president’s actions and accomplishments,” a visibly subdued Spicer told interviewer Greta Van Susteren at a Newseum event examining the press in Trump's first 100 days.

“When you’re distracting from that message of accomplishment, and your job is to be the exact opposite, on a professional level it’s disappointing because I think I’ve let the president down. On both a personal level and a professional level, that will not go down as a very good day in my history,” he added.

A day earlier, Spicer said Hitler did not use chemical weapons during World War II, comparing the Nazi leader to Syrian leader Bashar Assad’s use of chemical weapons on his own citizens. "There's no comparing atrocities," a contrite Spicer said Wednesday. "Of all weeks, this compounds that kind of mistake.”

"It's painful to myself to know I did something like that.”

Spicer also said the mistake was particularly "really painful" because Trump has enjoyed an "unbelievable" run of good news lately, including his Syrian airstrikes and the confirmation of Justice Neil Gorsuch to the Supreme Court. "From a professional standpoint. the president had a phenomenal couple of weeks. And unbelievable successful couple of weeks" even if some would disagree.

During Tuesday’s press briefing, Spicer said: “You had someone as despicable as Hitler who did not even sink to using chemical weapons.” Later in the briefing, given a chance to walk back his comments, Spicer continued the comparison, claiming that Hitler did not “gas his own people,” and referred to concentration camps as “Holocaust centers.”

His remarks drew harsh criticism and ridicule from politicians on both sides of the aisle and Jewish interest groups. Spicer eventually apologized for his comments