Iran activated its air defences in several regions on Saturday and Israel told its citizens to take shelter ahead of a fresh barrage of missiles, as the arch-foes exchanged massive strikes in their fiercest direct confrontation in history.

Shapiro served as Deputy Assistant Secretary of Defense for the Middle East until January—charged with, among other things, considering scenarios in which tensions between Israel and Iran escalated into all-out war and preparing U.

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 country’s exports mostly come from Kharg Island in the Persian Gulf. But Israel’s energy facilities are also at risk.

Iran has told the United States and UK that it could retaliate if the countries aid Israel in attacks amid fears the Middle East will descend into war.

Iran missiles enter Israeli airspace as RAF jets deployed to Middle East - Israeli Prime Minister Benjamin Netanyahu warns: ‘What they have felt so far is nothing compared with what they will be hande

DUBAI, United Arab Emirates — Israel’s defense minister warned Saturday that “Tehran will burn” if Iran continues firing missiles, as the two countries traded blows a day after Israel launched a blistering surprise attack on Iranian nuclear and military sites, killing a number of top generals.

The United States has pulled some diplomatic staff and military families out of the Middle East, citing unspecified regional security risks.

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.