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, United Arab Emirates (AP) — Israel unleashed airstrikes across Iran for a third day on 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 off-ramp, were canceled.

Israel has said it launched Operation Rising Lion to deal a blow to Iran’s nuclear ambitions. Prime Minister Benjamin Netanyahu has claimed that the strikes are essential to ‘roll back the Iranian threat to Israel’s very survival’ and that Tehran could build a nuclear weapon within a few months.