US President Donald Trump sent a fresh warning to Iran’s leaders as US military forces amass in the region, the latest sign that diplomatic negotiations between Washington and Tehran could be breaking down.
“I would say he should be very worried, yeah. He should be,” Trump said in an interview with NBC News on Wednesday, when asked about Iran’s supreme leader. “As you know, they are negotiating with us.”
Trump’s remarks come after Secretary of State Marco Rubio said Washington is open to coming…


