Israel's deputy prime minister says the nuclear talks between Iran and Western powers in Istanbul last week may have been a stalling tactic by Tehran.
Danny Ayalon, of the hawkish Israel Beitenu Party, is cautioning against "falling into the trap of a good atmosphere."
He says the lapse of nearly a year and a half since a previous summit failed was "wasted" time.
Ayalon is urging the international community to tighten sanctions on Tehran immediately, rather than wait until July as planned. He spoke to reporters Wednesday in Jerusalem.
Iran claims its nuclear program is peaceful, but Israel and the West think it seeks to develop atomic weapons. Israel has not ruled out a military strike if Iran doesn't abandon the program's suspect elements.