The closure of the critical waterway deals a blow to efforts to end the US-Iran conflict, as negotiators downplayed the prospects of a breakthrough at talks in Switzerland.

Iran re-shut the Strait of Hormuz Friday, citing US regional military presence and Israel's actions in Lebanon, despite a recent memorandum signed by both nations' leaders.

TEHRAN/JERUSALEM -- Iran's main military command Khatam al-Anbiya Central Headquarters announced Saturday the closure of the Strait of Hormuz, citing US "breach" of the…