(CNN) -- Israeli Justice Minister Tzipi Livni says "it is clear for us here in Israel" that chemical weapons have been used in Syria, and an international response to the crisis should be "on the table in the discussions between Prime Minister Netanyahu and President Obama" during the president's trip to Israel.
When pressed during an interview in her Tel Aviv home, Livni wouldn't say whether there is evidence that the regime of Syrian President Bashar al-Assad has directed the use of any chemical weapons.
But she said this development poses a direct threat to Israel, which shares a border with Syria. Livni told CNN that "the appearance is that it's not going to be only in Syria, but that Hezbollah can reach all these chemical weapons and use them against Israel in the future."
Israelis have long been concerned that Hezbollah, Israel's foe in neighboring Lebanon, could gain possession of Syrian chemical weapons if the Assad regime is further destabilized.
President Obama just landed in Israel for a two-day trip, and two national security issues dominate the agenda: the nuclear showdown with Iran and the growing crisis with Syria. On both fronts, Livni says, U.S. leadership can make the crucial difference.
"The United States has the tools in order to prevent Iran from having a nuclear weapon and in order to stop all this situation in Syria," she said, and she insisted that this is the time to act.
"It is not a favor to the state of Israel. This is something that represents the interests of the United States as well," she said.
In February, Israel attacked a convoy of anti-aircraft weapons in Syria. That assault did not involve chemical weapons, but clearly their use would increase the stakes for Israel. Livni says Israel is prepared to take action: "Yes, but I am not going to speak about it publicly. Israel has the right of course to defend itself."
There are reports that chemical weapons were used in two locations Tuesday in Syria, killing at least 25 people.
On Tuesday night, U.S. House Intelligence Committee Chairman Mike Rogers told CNN there was a "high probability to believe that chemical weapons were used." And in the same interview, Senate Intelligence Committee Chairwoman Diane Feinstein said "the White House has to make a decision in this. I think the days are becoming more desperate."