The head of the International Atomic Energy Agency says there is a possibility of both radiological and chemical contamination within Iran’s main nuclear enrichment facility in Natanz.

Israel and Iran have begun a new round of attacks, as the conflict between the two heavily armed rivals enters its fourth day.

The latest attacks have come amid growing concern over Iran’s nuclear program, prompting questions over what this means for the global non-proliferation regime.

European foreign ministers told their Iranian counterpart in a call on Monday to return to nuclear negotiations with the U.S. and refrain from escalating conflict with Israel, to which Iran's foreign minister said Tehran's priority was to confront Israel for now,

After canceling negotiations with the U.S. scheduled for Sunday, Tehran has signaled it is willing to talk.

Smoke and flames filled the sky over Tehran as Israel struck oil and gas facilities in the Iranian capital and targeted more nuclear facilities during attacks that carried on into Sunday after starting two days earlier.

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.

The decision comes as officials say they believe that Israel is preparing to launch a military attack on Iran. Tehran condemned the vote.