Iran is seeking to open a "third front" against Israel using Hezbollah fighters on the Syrian Golan Heights, Prime Minister Benjamin Netanyahu said on Sunday.
Netanyahu said Tehran's attempts to entrench itself along Israel's borders was one of the biggest emerging security threats facing the Jewish state.
"Alongside Iran's direct guidance of Hezbollah's actions in the north and Hamas's in the south, Iran is trying also to develop a third front on the Golan Heights via the thousands of Hezbollah fighters who are in southern Syria and over which Iran holds direct command," he said.
Speaking at the start of the weekly cabinet meeting, Netanyahu said his ministers were to be briefed on "the security challenges developing around us, first and foremost Iran's attempt to increase its foothold on Israel's borders even as it works to arm itself with nuclear weapons."
An Israeli air strike inside the Syrian-controlled sector of the Golan Heights on January 18 killed six members of Hezbollah, which is backed by Iran and allied with Syrian President Bashar al-Assad, as well as a general from Iran's elite Revolutionary Guards.
Israel neither confirmed nor denied responsibility, but it has carried out several such strikes over the past two years, stressing its policy of preventing arms transfers to militant groups and potential attacks.
Netanyahu said that Tehran's ongoing "murderous terrorism" has "not prevented the international community from continuing to talk with Iran about a nuclear agreement that will allow it to build the industrial capacity to develop nuclear weapons."
World powers are trying to strike a deal with Iran that would prevent Tehran from developing a nuclear bomb in return for an easing of punishing international economic sanctions.
Israel has repeatedly warned that Iran's nuclear programme has military objectives, a claim Tehran denies.
US Secretary of State John Kerry was set to arrive in Geneva Sunday for renewed talks with his Iranian counterpart on Tehran's nuclear programme, after warning "significant gaps" remain ahead of a key deadline.