A sixth round of nuclear talks between the United States and Iran, previously scheduled for Sunday, was canceled amid escalating tensions between Israel and Iran.

DUBAI — Israel unleashed airstrikes across Iran for a third day Sunday and threatened even greater force as some Iranian missiles evaded Israeli air defenses to strike buildings in the heart of the country. Planned talks on Iran’s nuclear program, which could provide an offramp, were canceled.

The push to do a deal on the country’s nuclear program could be revived, even after the Israeli strikes scuppered the latest round of talks.

Israel and Iran have continued to trade heavy missile strikes overnight as Donald Trump threatens to respond 'at levels never seen before' if Tehran attacks US bases.Posting on Truth Social, the US president said his forces had “nothing to do with the attack on Iran,

The United States is the main international backer of Israel, Iran's biggest regional foe. It is also a close ally of Sunni Gulf monarchies which for years pursued their own rivalry with the Islamic Republic, seeing it as their main regional threat.

The strikes came after the Israeli military said it had carried out fresh strikes on Iran nuclear infrastructure sites.

Experts suggest the U.S. has a strategic opportunity to leverage Iran's weakened position for a nuclear deal after Israel's targeted strikes on Iranian nuclear and military sites.

Interviews with half a dozen senior Iranian officials show that they were not expecting Israel to strike before another round of talks.