Iran said on Friday the dialogue with the U.S. over Tehran's nuclear programme is "meaningless" after Israel's biggest-ever military strike against its longstanding enemy, accusing Washington of supporting the attack.

"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," the semi-official Tasnim news agency quoted foreign ministry spokesperson Esmaeil Baghaei as saying.

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

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 programme.

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.

Earlier, Oman News Agency and Iranian state media had reported that the talks have been suspended indefinitely.

“Israel’s unilateral attack on Iran is illegal, unjustifiable and a grave threat to regional stability,” Oman Foreign Minister Badr Albusaidi posted on the social platform X after the attacks. “I condemn it and urge the global community to come together to reject Israeli aggression and support de-escalation and diplomacy with one voice.”