President Donald Trump told top aides on Tuesday evening that he had approved plans for an attack on Iran but had not yet issued a final order to determine whether Tehran would abandon its nuclear programme, according to three people familiar with the matter. Mr. Trump has said publicly that a military strike is an option since he gave secret instructions to the military in the White House Situation Room. "I have some ideas about what to do, but I haven't made a final decision - I would prefer to make a final decision one second before the deadline," he told reporters on Wednesday. By threatening to join Israel in an attack on Iran, Mr. Trump is hoping to force Iran to meet his demands, people familiar with the matter said. He acknowledged that the United States was considering an attack, but he said he could still decide not to launch an attack.