Tehran: Tehran has declared ongoing nuclear negotiations with the United States "pointless" following Israel's largest-ever military offensive against Iran, accusing Washington of enabling the assault and sabotaging diplomatic efforts.

"The behavior of the United States renders dialogue meaningless," said Iranian Foreign Ministry spokesperson Esmaeil Baghaei, as quoted by the semi-official Tasnim news agency. "You cannot speak of negotiations while simultaneously allowing the Zionist regime to attack our territory."

Baghaei further alleged that Israel had deliberately disrupted the negotiation process and would not have launched such a large-scale operation without the tacit approval of the U.S.

Earlier, Iran formally accused Washington of complicity in the attacks. While the U.S. dismissed the accusation, its representatives at the United Nations urged Iran to return to the table, saying it would be “wise” to continue talks regarding its nuclear program.

The planned sixth round of U.S.-Iran negotiations, scheduled for Sunday in Muscat, is now in doubt as tensions soar in the aftermath of the Israeli strikes.

Iran maintains that its nuclear program is strictly for peaceful, civilian purposes, dismissing long-standing Israeli claims that it is working toward a nuclear weapon.

Meanwhile, U.S. President Donald Trump acknowledged that American officials were aware in advance of Israel’s planned operation but insisted that a diplomatic agreement with Tehran was still possible.