UN Secretary General Antonio Guterres is concerned about Israel's strikes on Iran's nuclear facilities and calls on the parties to exercise maximum restraint, said Farhan Haq, Deputy Spokesman for the Secretary General, in a statement.

"The Secretary-General condemns any military escalation in the Middle East. He is particularly concerned by Israeli attacks on nuclear installations in Iran while talks between Iran and the United States on the status of Iran's nuclear programme are underway. The Secretary-General recalls the obligation of UN Member States to act in accordance with the UN Charter and international law," the statement said.

"The Secretary-General asks both sides to show maximum restraint, avoiding at all costs a descent into deeper conflict, a situation that the region can hardly afford," Haq added.

Earlier, the Israeli authorities announced military strikes on Iran, including on nuclear facilities in different parts of the country. Israeli Prime Minister Benjamin Netanyahu said the operation was aimed at disrupting Iran's nuclear program and warned that more strikes would follow.