Iran warned on Sunday that any major new attack by the United States and its allies would trigger sustained retaliation, saying it had information that such an operation was being prepared as tensions rose across the Middle East.Iran's military central command said any new attack would be met with retaliation against US bases and interests, while Washington's regional allies would be considered parties to the conflict.The warning came amid mounting tensions with US President Donald Trump, later, also issuing a fresh warning to Tehran. Trump said Iran would face severe consequences if it did not agree to a deal, including economic collapse or attacks on its leadership and warned that "very big things" could happen.The US State Department had on Saturday warned Americans in the region of the potential for "unforeseen escalation", urging them to exercise greater vigilance and prepare for possible flight cancellations and airspace closures.The latest exchange followed a fresh escalation involving Yemen's Iran-backed Houthis, who claimed attacks on Saudi targets including Riyadh and an oil facility in the Red Sea port of Yanbu.

Saudi Arabia did not immediately comment on the claims, while a Saudi-led coalition said it had foiled other attacks.The nearly seven-month-old US-Iran war has already disrupted energy supplies and shipping across the region. Iran has continued to block most shipping through the Strait of Hormuz and said it would not reopen the waterway until the terms of a June ceasefire agreement, as Tehran interprets them, are met.