Israel has escalated its bombardment of Iranian cities, including Tehran's state television headquarters; Iranian missiles have struck Tel Aviv.

President Donald Trump in about eight hours went from suggesting a nuclear deal with Iran remained “achievable” to urging Tehran’s 9.5 million residents to flee for their lives as he cut short his visit to an international summit to return to Washington for urgent talks with his national security team.

Israeli strikes on Natanz, Fordow and Isfahan pose little regional radiation risk but could release plumes of toxic chemicals, experts said.