Iran said the dialogue with the U.S. over Tehran's nuclear program is "meaningless" after Israel's biggest-ever military strike against its longstanding enemy, but said it is yet to decide on whether to attend planned talks on Sunday.

"The other side (the U.S.) acted in a way that makes dialogue meaningless. You cannot claim to negotiate and at the same time divide work by allowing the Zionist regime (Israel) to target Iran's territory," state media on Saturday quoted foreign ministry spokesperson Esmaeil Baghaei as saying.

"It is still unclear what decision we will make on Sunday in this regard," Baghaei was quoted as saying.

He said Israel "succeeded in influencing" the diplomatic process and the Israeli attack would not have happened without Washington's permission, accusing Washington of supporting the attack.

Iran earlier accused the U.S. of being complicit in Israel's attacks, but Washington denied the allegation and told Tehran at the United Nations Security Council that it would be "wise" to negotiate over its nuclear program.

The sixth round of U.S.-Iran nuclear talks was set to be held on Sunday in Muscat, but it was unclear whether it would go ahead after the Israeli strikes.

Iran denies that its uranium enrichment program is for anything other than civilian purposes, rejecting Israeli allegations that it is secretly developing nuclear weapons.

U.S. President Donald Trump told Reuters that he and his team had known the Israeli attacks were coming but they still saw room for an accord.