DUBAI/WASHINGTON, April 29 -- Efforts to end the Iran conflict were at an impasse on Tuesday with US President Donald Trump unhappy at the latest plans from Tehran, which he said had informed the US it was in a "state of collapse" and figuring out its leadership situation. Iran's most recent proposal on resolving the two-month war would set aside discussion of its nuclear programme until the conflict was concluded and disputes over shipping resolved. Trump wants nuclear issues dealt with from the outset, a US official briefed on Trump's Monday meeting with his advisers said. White House spokeswoman Olivia Wales said the US has "been clear about our red lines" as it seeks to end the war it began in February alongside Israel. In a post on Tru...