TEHRAN, Iran (AP) - Iran's supreme leader has rejected proposals for direct talks with United States, apparently quashing suggestions for a breakthrough dialogue on the nuclear standoff and other issues. Thursday's statement posted on Ayatollah Ali Khamenei's website marks his first reaction to the proposals for the one-on-one talks, which received cautious support last week from Iran's foreign minister. But Khamenei has the final say in all key matters and has previously opposed direct talks with Washington. Iran and six world powers, including the U.S., are scheduled to resume nuclear negotiations later this month.