Israel’s envoy to the United Nations on Tuesday voiced concern that Syrian President Bashar Assad’s chemical weapons stockpile could fall into the hands of Hezbollah, and called for international action to prevent it from happening.

Speaking at a day-long UN Security Council discussion of counter-terrorism, Ambassador Ron Prosor said the world faces “the frightening possibility that Hezbollah could soon get its hands on Assad’s vast stockpiles of chemical weapons.” He urged the Security Council and world leaders to “act today, not tomorrow” to ensure Assad’s arsenal doesn’t fall into the hands of terrorists.

“We have a responsibility to prevent the world’s most dangerous weapons from falling into the hands of the world’s most dangerous actors,” Prosor said.

Although the Syrian government has never confirmed its possession of chemical weapons, it is suspected of having large stockpiles of sarin, VX, and mustard gas. According to a cable leaked to Foreign Policy magazine on Tuesday, US State Department officials suspect that the Assad regime used chemical weapons in an attack on rebels in Homs last month.

Prosor also assigned specific blame to Iran for what he described as its unchecked sponsorship of international terrorism, including assisting Hezbollah to amass an arsenal of missiles 50,000 strong.

“This Council cannot turn a blind eye to those states that sponsor, support, and arm terrorists,” he said.

UN Secretary-General Ban Ki-moon told the assembly that “terrorism festers where conflicts are endemic … and where human rights, human dignity and human life are not protected and impunity prevails.”

“We have to drown out shrill appeals to intolerance and extremism with sound calls for compassion and moderation,” Ban said. “We have to replace the terrorist narrative with messages of peace, development and human welfare.”

Prosor reiterated the secretary-general’s statements, saying that combatting terrorism requires “disrupting the ecosystem of extremism in which terror thrives” through the advancement of education that promotes peace and mutual understanding and denounces incitement.

“We are far from that reality,” Prosor said. “In too many corners of the planet, all of the elements remain in place for extremists to grow the next generation of terrorists.”

“In this very Council, some states offer justification for certain terrorists, while condemning others,” he said in a possible allusion to Iran.