Israel’s attack on Iran was long in the making – the result of years of meticulous planning by Israel and days of high-stakes talks between Tel Aviv and Washington, officials told CNN.

The sweeping attacks by Israel, which began early Friday, have killed more than 70 people, including four of Iran’s top security chiefs, and damaged Iran’s main nuclear site at Natanz. Iran retaliated by launching scores of missiles at Israel. At least three people have been killed and dozens more wounded during these attacks.

In remarks before the UN Security Council, Iranian Ambassador Amir Saeid Iravani claimed that 78 people had been killed in Israeli attacks across Iran -- using the term "martyred" -- and that another 320 had been injured.

Israel's widespread airstrikes against Iran's nuclear program are stoking fears of a larger confrontation.

US President Donald Trump has urged Iran to make a deal on its nuclear programme, warning of "even more brutal" Israeli attacks - Iran accuses the US of supporting Israel's strikes, which the US denies