Pakistan, June 22 -- Tensions in the Middle East soared on Sunday as Iran announced the closure of the strategic Strait of Hormuz and vowed to target U.S. military positions following American strikes on its nuclear facilities.

The Strait of Hormuz is a vital shipping route through which a large share of the world's oil supply flows. Its shutdown threatens to disrupt global energy markets and raises fears of a wider military conflict. Iran's move came in direct response to U.S. airstrikes on three nuclear sites inside the country.

Iran's Supreme Leader Ayatollah Ali Khamenei warned the U.S. that it had entered a war that would bring more damage to itself than to Iran. Foreign Minister Abbas Araghchi called the U.S. strikes "shameful" an...