U.S. Secretary of State Antony Blinken on Friday refused to comment on reports of an attack by Israel on Iran, beyond saying Washington was "not involved in any offensive operation".
Speaking to journalists after a meeting with G7 counterparts in Italy, he declined to answer repeated questions about explosions in Iran, and reports that Israel had carried out retaliatory strikes.
"I'm not going to speak to these reported events... All I can say is for our part and for all the members of the G7 our focus is on de-escalation", Blinken told a press conference on the island of Capri.
"The US has not been involved in any offensive operation," he said.
Speaking to reporters earlier, G7 host Antonio Tajani, the foreign minister of Italy, said Washington had been informed in advance of the strikes, without giving details.
"The United States were informed at the last moment," he said, adding that "it was just information" passed on -- without saying who by.
The reports dominated the G7 Friday, with Tajani forced to change the agenda, but little public information emerged.
In its final statement, the Group of Seven ministers said: "In light of reports of strikes on April 19th, we urge all parties to work to prevent further escalation. The G7 will continue to work to this end."
Israel had warned it would hit back after Iran fired hundreds of missiles and drones at Israel almost a week ago, in retaliation for a deadly strike -- which Tehran blamed on its foe -- that levelled Iran's consular annex at its embassy in Syria.