An Iranian television anchor fled her studio during a live broadcast as Israeli bombs fell on the headquarters of the country's state-run TV station.
Israel's military said the state media building served as a communications centre used by Iran's armed forces.
Earlier, the military had issued an evacuation warning to 330,000 people in a part of central Tehran that houses the country's state TV and police headquarters, as well as three large hospitals, including one owned by Iran's paramilitary Revolutionary Guard.
Trump was due to leave the G7 summit in Canada, a day early, due to the Middle East situation, the White House said.
Fox News reported he would convene his National Security Council.
"Iran should have signed the 'deal' I told them to sign. What a shame, and waste of human life. Simply stated, IRAN CAN NOT HAVE A NUCLEAR WEAPON. I said it over and over again! Everyone should immediately evacuate Tehran!" Trump wrote on his Truth Social media platform.
Political outlet Axios reported the US is discussing with Iran the possibility of a meeting this week between US envoy Steve Witkoff and Iranian Foreign Minister Abbas Araghchi for restarting talks on a nuclear deal and an end to the conflict between Israel and Iran.
Prime Minister Benjamin Netanyahu said the Israeli strikes have set Iran's nuclear program back a "very, very long time."
He added Israel is not attempting to topple the Iranian government, but he said he would not be surprised if that happened as a result of the strikes.
"The regime is very weak," Netanyahu told a news conference.
Iran's Foreign Minister Abbas Araqchi told four European counterparts that Iran was serious about diplomacy but its current focus was on confronting aggression, Iranian state media reported. Israel has said its goal is to eliminate Tehran's ability to develop a nuclear weapon.
Iran says more than 224 Iranians have been killed, most of them civilians. Israel says 24 people have been killed, all of them civilians.
"If President Trump is genuine about diplomacy and interested in stopping this war, next steps are consequential," Araqchi said on X.
"Israel must halt its aggression, and absent a total cessation of military aggression against us, our responses will continue. It takes one phone call from Washington to muzzle someone like Netanyahu."
Speaking to Reuters on Friday, the first day of Israel's assault, Trump said he had given the Iranians 60 days to come to an agreement to halt uranium enrichment and that the time had expired with no deal.
Talks between the United States and Iran, hosted by Oman, had been scheduled for Sunday but were scrapped, with Tehran saying it could not negotiate while under attack.
Iranian media said Iran was preparing for the "largest and most intense missile attack" yet against Israel, including against military and intelligence targets.
Israel launched its air war with a surprise attack that killed nearly the entire top echelon of Iran's military commanders and its leading nuclear scientists. It says it now has control of Iranian airspace and intends to escalate the campaign in coming days.
Israel said it hit Iranian F-14 fighter planes at Tehran airport on Monday, and its air strikes have also put at least two of Iran's three operating uranium enrichment plants out of action.
with AP
