Foreign Minister Avigdor Liberman on Tuesday said any attempt by Hezbollah to attain non-conventional weapons from Syria would prompt Israeli military intervention. He also commented on the Iranian nuclear threat, saying that “negotiations must end and actions must begin.”

“In the moment we see that the Syrians transfer chemical and biological weapons to Hezbollah, this is a red line for us, and from our point of view it’s a clear casus belli,” Liberman said at a press conference in Brussels. “We will act decisively and without hesitation or restraint. It will be a completely different ballgame. And we hope for the understanding from the international community and we hope for cooperation.”

At the same time, Israel Defense Forces Chief of Staff Benny Gantz told a Knesset panel that an attack on Syria’s chemical weapons stockpiles could lead to a wider regional conflict.

Gantz said Israel would be hard pressed to carry out an effective pinpointed attack, and a more wide-ranging strike could drag the country into a war.

He added that Syria was still in control of its chemical weapons, but that could change.

Israeli officials have hinted over the last few days that they may be forced to take action to prevent Syria’s weapons from falling into the wrong hands.

Speaking Tuesday, Liberman said Israel’s worries are not merely based on over-anxious suspicions but on proven facts. “We have enough information about [Hezbollah’s] desire, their attempt to achieve chemical and biological weapons. It’s our biggest concern.”

Liberman was speaking at the conclusion of the annual European Union-Israel Association Council, during which the two parties reviewed and expanded trade and political relations.

On Monday, Liberman met with his French counterpart, Laurent Fabius, and said that Israel was “refraining from any sort of intervention [in Syria], beyond Israel’s expressed willingness to extend humanitarian aid to the injured,” according to a statement released by the Foreign Ministry in Jerusalem. “However, any attempt to transfer chemical weapons from Syria to the Hizbullah will be considered crossing a red line and Israel will not hold back and will respond decisively if this happens.”

During Tuesday’s press conference, Liberman also reiterated Israel’s claim that Hezbollah and Iran were behind several terror attacks and attempted bombings targeting Israelis and other nationals, including a suicide attack in Bulgaria last week that killed five Israeli tourists. “We think that we know, and we have real hard evidence that the one who stands behind these attacks is Hezbollah and the Iranians,” he said.

The foreign minister also commented briefly on Iran’s race toward a nuclear weapons capability and the international community’s attempts to halt Iran’s ambitions through several fruitless rounds of negotiations.

Now was the “right timing to draw some conclusions: we cannot negotiate forever,” Liberman said. “The time will come when negotiations must end and actions must begin. We have patience, we’re waiting, we’re anxiously monitoring these talks, but we also hope to see substantial results.”