The man-made nerve agent sarin gas was indeed used in last week's attack in northern Syria that killed more than 80 people, a Turkish official said Tuesday, citing autopsy results.
Bblood and urine samples taken from victims confirmed that they were subjected to sarin, according to Recep Akdag, Turkey’s health minister, speaking to the state-run news agency Anadolu.
Turkey last week conducted autopsies on three victims of the gas attack. Officials from the World Health Organization and Organization for the Prohibition of Chemical Weapons participated in the autopsies.
The April 4 attack on the rebel-held town in Idlib province left nearly 90 people dead. The United States blamed President Bashar Assad's government and launched nearly 60 cruise missiles on Friday at the Shayrat air base in the central province of Homs, where it claims the attack originated.
Turkish officials publicly claimed early on that sarin was used, The New York Times reported.
Also on Tuesday, Russian President Vladimir Putin dismissed the suggestions the Syrian government could be behind the attack in Idlib province.
Putin told reporters that Russia knew about planned "provocations" to blame Syria's government for using chemical weapons. He said the U.N. should first investigate the attack.
"It reminds me of the events in 2003 when U.S. envoys to the Security Council were demonstrating what they said were chemical weapons found in Iraq," Putin said. "We have seen it all already."
Col. Gen. Sergei Rudskoy of the Russian General Staff said in televised remarks that Russia will provide security for international inspectors seeking to examine Syrian bases, and that Damascus has agreed to allow the inspections.
U.S. Secretary of State Rex Tillerson is in Moscow to meet with Russian officials about the Syria civil war. It is the first official trip to Russia by a member of President Donald Trump's Cabinet. It's unclear if Putin and Tillerson will meet.
Before heading to Russia, Tillerson told reporters that Moscow had either failed to take seriously its obligation to rid Syria of chemical weapons, or had been incompetent. But, he said, the distinction "doesn't much matter to the dead."
His trip follows Monday's claim by a senior U.S. official that Washington has concluded Russia knew in advance of Syria's chemical weapons attack. The official, who wasn't authorized to speak publicly on intelligence matters and demanded anonymity, didn't offer concrete proof and others in the Trump administration cautioned that no final determination of Russia's foreknowledge had been made.
"We cannot let this happen again," Tillerson said of the chemical attack.
"We want to relieve the suffering of the Syrian people. Russia can be a part of that future and play an important role," Tillerson added in remarks to reporters. "Or Russia can maintain its alliance" with Syria and Iran.
Russia's foreign ministry said in a statement that it hoped for "productive talks." It said the outcome of the discussions is important not only for the U.S.-Russian relationship, but "for the overall atmosphere on the world stage."
The United States has sought to minimize expectations for the trip or the likelihood that the U.S. will leave with any Russian concessions on Syria. Instead, the U.S. is hoping to use the visit — the first by a Trump Cabinet official to Russia — to convey expectations to Moscow and allow Russians time to respond.
Though intended to punish Assad for a chemical weapons attack, the U.S. strikes last week also served to refocus the world's attention on the bloody war in Syria. In Italy, diplomats spoke of possible new sanctions on Syria's and Russia's militaries, and additional U.S. military action if Assad's forces continue attacking civilians.
The Associated Press contributed to this report.