( 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 would n'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 . Israeli minister says she hopes U.S. helps restart peace talks . 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 . ''
An international response should be `` on the table '' amid Obama visit , justice minister says . She does n't say if there 's evidence that Syrian leader ordered use of the weapons . Syria crisis and Iran nuclear showdown are among top issues as Obama visits Israel . Tzipi Livni says U.S. leadership can make a crucial difference on both fronts .