TEL AVIV, Israel — Israel and Iran traded strikes a week into their war on Friday as President Donald Trump weighed U.S. military involvement and key European ministers met with Iran’s top diplomat in Geneva in a scramble to de-escalate the conflict.

But the first face-to-face meeting between Western and Iranian officials in the weeklong war concluded after four hours with no sign of an immediate breakthrough.

To give diplomacy a chance, Trump said he would put off deciding for up to two weeks whether to join Israel’s air campaign against Iran. U.S. participation would most likely involve strikes against Iran’s underground Fordo uranium enrichment facility, considered to be out of reach to all but America’s “bunker-buster” bombs.

Whether or not the U.S. joins, Israeli Prime Minister Benjamin Netanyahu said Israel’s military operation in Iran would continue “for as long as it takes” to eliminate what he called the existential threat of a nuclear-armed Iran. Israel’s top general echoed the warning, saying the Israeli military was ready “for a prolonged campaign.”

As the talks ended in Switzerland, European negotiators expressed hope for more negotiations in the future. Iran’s top diplomat said he was open to further dialogue.

But Foreign Minister Abbas Araghchi emphasized that Tehran had no interest in negotiating with the U.S. while Israel continued attacking. Israel said its warplanes hit dozens of military targets in Iran early Friday, including missile-manufacturing facilities.

“Iran is ready to consider diplomacy if aggression ceases and the aggressor is held accountable for its committed crimes,” he said in a statement.

Iran previously agreed to limit its uranium enrichment and allow international inspectors access to its nuclear sites under a 2015 deal with the U.S., France, China, Russia, Britain and Germany in exchange for sanctions relief.