WASHINGTON — Even as Iran’s supreme leader suggested another hurdle to a nuclear deal Thursday, President Barack Obama and his administration waged an aggressive coordinated campaign to stop Congress from interfering.Making his first public comments on the deal, Ayatollah Ali Khamenei said the deal would be signed in late June only if economic sanctions are lifted at once — not in phases as the Obama administration insists.“This is a very crucial point that on the day of nuclear deal all sanctions be removed,” he said.Obama did not acknowledge the remarks out of Tehran as he spoke in Jamaica, but he said he was confident that the framework would ensure that Iran didn’t obtain nuclear weapons, keeping his focus at least publicly on selling the pact in the U.S.“This is not done until it’s done,” Obama said in Kingston after a meeting with Jamaican Prime Minister Portia Simpson Miller.