Washington/Tehran, March 26 -- US President Donald Trump has urged Iran to "get serious soon" in negotiations, warning the Islamic Republic that its time is running out even as indirect efforts to end the war continue through regional intermediaries.

Working via Pakistan, Egypt and Turkey, Washington has proposed a high-level meeting to discuss a framework for de-escalation, as Trump's five-day pause on strikes against Iranian energy infrastructure is due to expire on Saturday, raising the risk of renewed escalation - particularly if disruptions along the Strait of Hormuz continue.

US officials said that contingency planning is under way, with explorations ongoing for a 'final blow'. This includes several options ranging from expanded air...