Defense Minister Avigdor Liberman accused Syrian President Bashar Assad of being directly responsible for a chemical attack this week that left scores dead and spurred international outrage and calls for action against Damascus.

In an interview with the Yedioth Ahronoth daily published Thursday, Liberman said that he has “100 percent certainty” that Assad himself was directly responsible for the attack, but also said Israel would not become involved militarily to stop the bloodshed.

“The murderous chemical weapons attacks on citizens in Idlib province in Syria and on a local hospital were carried out on the direct order and planned by the Syrian president, Bashar Assad, using Syrian planes,” he said.

The attack on the rebel-held village of Khan Sheikhoun, in which at least 72 people were killed, among them 20 children, has been blamed on Assad by the US and EU, among others.

Syria’s army has denied any use of chemical weapons, as has its patron Russia, saying it “has never used them, anytime, anywhere, and will not do so in the future.”

This photo provided Tuesday, April 4, 2017 by the Syrian anti-government activist group Edlib Media Center, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. (Edlib Media Center, via AP)

This photo provided Tuesday, April 4, 2017 by the Syrian anti-government activist group Edlib Media Center, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. (Edlib Media Center, via AP)

Liberman’s comments were the strongest denunciation against the Syrian regime yet by a named Israeli official, ostensibly putting Jerusalem on a collision course with Moscow, which it has tried to court as an ally.

Asked if Russia, which has become the Assad regime’s primary military backer since it began intervening in the six-year-long Syrian conflict in September 2015, was involved in the chemical weapons attack, Liberman said “we don’t know.”

“We do know this is a Syrian operation by Assad from A to Z,” he said.

However, he said Israel, which has largely stayed out of the Syrian conflict, would continue to eschew involvement, saying the matter was the responsibility of the international community.

“Why do we need to take the chestnuts out of the fire? This is the responsibility of the international community. I am not prepared to be the schmuck that the whole world pisses on,” he said.

“The [rest of] the world should take responsibility instead of just saying it will,” he added.

On Wednesday, defense officials told the Associated Press that Israeli military intelligence believes Assad’s forces were behind the chemical attack.

The officials, speaking on condition of anonymity, said that Israel believes Assad has tons of chemical weapons currently in his arsenal, despite a 2013 agreement in which Syria consented to hand over its stockpiles of chemical weapons for destruction.

Liberman also said that the subsequent bombing of the hospital where victims of the attack were being treated also involved the use of chemical weapons, a claim not made elsewhere.

A picture taken on April 4, 2017 shows destruction at a hospital room in Khan Sheikhoun, a rebel-held town in the northwestern Syrian Idlib province, following a suspected toxic gas attack. (AFP/ Omar haj kadour)

A picture taken on April 4, 2017 shows destruction at a hospital room in Khan Sheikhoun, a rebel-held town in the northwestern Syrian Idlib province, following a suspected toxic gas attack. (AFP/ Omar haj kadour)

“The same wounded people who were evacuated from the area of the bombardment to the hospital, were attacked for a second time with chemical weapons when the planes of the Syrian army bombarded the hospital,” he said.

Liberman did not say what intelligence the claim was based on.

Liberman’s comments were the first by a senior Israeli official directly pinning the blame for the latest use of chemical weapons in Syria on the Assad regime.

On Tuesday, Prime Minister Benjamin Netanyahu said he was “shocked and outraged” by the attack, yet did not make any mention of Assad, possibly to avoid irking Russia, with which Israel has tried to foster strong relations in order to maintain its ability to carry out on airstrikes in the country to thwart weapons transfers to the Hezbollah terror group, which is fighting alongside Assad’s forces.

Liberman said the “nonexistent” response from the international community shows that Israel can rely only on itself for its defense from weapons of mass destruction, pointing to the destruction of a secret Syrian nuclear reactor in 2007 widely attributed to Israel.

“There is no response from the international community. It is simply nonexistent. This brings me back to the realization that the State of Israel is obliged to only trust itself,” he said.

“Assad tried in the past to acquire a nuclear weapon with the help of North Korea, and the other gentlemen in the area like Hezbollah and [its leader Hassan] Nasrallah are no different from him.”

Prime Minister Benjamin Netanyahu and then-foreign minister Avigdor Liberman in the Knesset, February 3, 2014. (Yonatan Sindel/Flash90)

Prime Minister Benjamin Netanyahu and then-foreign minister Avigdor Liberman in the Knesset, February 3, 2014. (Yonatan Sindel/Flash90)

Liberman pointed to the attack as a reason why Israel has struggled to reach peace agreements with its neighbors, including Syria.

“The word peace is not relevant to the Middle East,” he said. “We can reach diplomatic arrangements but not peace.”

Agencies contributed to this report.