Israel's leader is heading to Russia to discuss an escalating crisis over Iran's nuclear program.
Israeli Prime Minister Benjamin Netanyahu is calling for tougher sanctions on Iran.
He was speaking to his Cabinet before heading to Russia, which has been reluctant to impose sanctions because of its strong business and military ties with Iran.
Mr. Netanyahu said Russia is an important "superpower" and an important friend of the state of Israel, and that Iran will top the agenda in his talks there. He said he would express Israel's view that "strong pressure" must be imposed on Teheran.
Iran says its nuclear program is for peaceful purposes. But last week, it began stepping up the enrichment of uranium to a higher grade, and Israel said the move is further proof that Iran is developing nuclear weapons.
The Iranian nuclear threat has aroused deep concern in Jerusalem because Iran's president has threatened to wipe Israel "off the map." Israeli leaders have repeatedly warned that they will not allow Iran to acquire nuclear weapons, and that if international diplomacy fails, Israel might launch a pre-emptive strike on Iran's nuclear facilities.
Israeli media said Mr. Netanyahu would press Russia not to sell sophisticated weapons to Iran. Israel is especially concerned about Russian anti-aircraft missiles that would improve Iran's defenses against a possible Israeli attack.