An Israeli tank patrols on Israel-occupied Golan Heights in southwestern Syria, on May 9, 2018, ahead of an Iranian missile attack on Israeli targets in the area. (AFP file photo)

JERUSALEM, Sept. 20 (Xinhua) -- Israel has upgraded and reinforced its nuclear facilities in the wake of Iranian threats, an Israeli official said Thursday.

"Israel cannot ignore the repeated and explicit threats, made by Iran and its proxies, to attack Israel's nuclear sites," a statement by the prime minister's office cited Israel Atomic Energy Commission Director General Zeev Snir as saying.

Snir made the remarks in a speech at the 62nd General Conference of the International Atomic Energy Agency (IAEA) in Vienna on Tuesday.

"These outrageous threats require Israel to take action and continue to protect and defend its nuclear facilities," Snir said.

"These facilities are constantly upgraded and reinforced, in line with IAEA safety guidelines, in order to withstand any attack," he added.

The Israeli atomic chief also urged the IAEA to conduct "a robust verification of Iran's clandestine activities."

"The covert Iranian nuclear weapons program is a documented fact," the statement noted.

Israel runs two official nuclear sites. Under its long-held "ambiguity policy," Israel has never confirmed or denied having nuclear weapons.