WATCH | Spicer compared the actions of Syrian President Bashar al-Assad with Adolf Hitler's.
UPDATE 6:16 p.m. EST:
Hours after White House press secretary Sean Spicer distastefully and falsely claimed that Adolf Hitler didn't use chemical weapons during WWII, he apologized for his remarks, which he admitted were "insensitive" and "inappropriate."
He continued, "It was a mistake. I shouldn't have done it. I won't do it again."
Spicer also claimed that he was trying to draw a comparison for which "there shouldn't have been one."
UPDATE 5:55 p.m. EST:
House minority leader Nancy Pelosi also called on Spicer to be fired after he made distasteful comments about the Holocaust.
UPDATE 4:45 p.m. EST:
The Anne Frank Center urged White House press secretary Sean Spicer to be fired after he falsely claimed that Adolf Hitler didn't resort to the use of chemical weapons during World War II.
The Executive Director of the center noted that Spicer's comments also came on Passover.
The statement continued, "Sean Spicer now lacks the integrity to serve as White House press secretary, and President Trump must fire him at once."
UPDATE 2:33 p.m. EST: White House Press Secretary Sean Spicer falsely said Adolf Hitler didn't "sink to the level of using chemical weapons" during his daily press briefings.
Spicer was referring to Bashar al-Assad.
He was quickly fact-checked.
UPDATE 1:09 p.m. EST: White House officials said Russia was involved in covering up Syria's use of chemical weapons, including the sarin nerve agent, USA Today reported.
Some U.S. officials believe Russia had advance knowledge of the chemical weapons attack, but no consensus has been established, aides told USA Today.
Syrian and Russian leaders have said the videos the U.S. is using as evidence are old or faked.
UPDATE 11:51 a.m. EST: Russian President Vladimir Putin claimed the Kremlin had information that the U.S. is planning to launch new airstrikes in Syria and fake chemical weapons attacks there, Reuters reported. He did not offer proof.
"We have information that a similar provocation is being prepared ... in other parts of Syria including the southern Damascus suburbs where they are planning to again plant some substance and accuse the Syrian authorities of using chemical weapons," Putin said at an event in Moscow with Italian President Sergio Mattarella.
BREAKING: Turkish health minister says test results confirm sarin gas was used in attack on northern Syrian town.— The Associated Press (@AP) April 11, 2017
UPDATE 9:45 a.m. EST: Turkey's health minister said tests confirmed sarin gas was used.
UPDATE 8:46 a.m. EST: Russian President Vladimir Putin said his country would appeal to the United Nations to investigate the Syrian chemical attack last week.
This came just hours after U.S. Secretary of State Rex Tillerson, who is set to visit Moscow later this week, condemned Russia for failing to stop Syria from stockpiling chemical weapons.
BREAKING: Russian President Vladimir Putin says Moscow will appeal to the UN to investigate the Syrian chemical attack.— The Associated Press (@AP) April 11, 2017
UPDATE April 11, 6:53 a.m. EST: Secretary of State Rex Tillerson, speaking at the G-7 conference on Tuesday, condemned Russia over Syria's chemical weapons use.
Tillerson said it was not clear whether Russia did not take its responsibility to curb Syria's chemical weapons use seriously or if it was merely "incompetent."
Here's a clip of Tillerson's comments.
ORIGINAL STORY: Russia knew of Syria's plans ahead of last week's chemical weapons attack, a senior U.S. official said.
The official said a Russian-operated drone flew over a hospital as victims of the attack were being rushed inside for treatment.
A few hours after the drone left, a Russian-made fighter jet reportedly bombed the hospital. American officials said this may have been an attempt to cover up the fact that chemical weapons were used.
Previously, U.S. officials said it was unclear whether the drone was operated by Russia or Syria.
The senior U.S. official who spoke to the Associated Press said it still isn't clear whether a Syrian or Russian was flying the jet that bombed the hospital.
The official, who spoke only on condition on anonymity, said the placement of the drone couldn't have been a coincidence.
The Associated Press contributed to this report.
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