TEHRAN — Iran’s supreme leader, Ayatollah Ali Khamenei, rejected any idea of bilateral talks with the United States in a speech in which he scoffed at Iranian officials who might consider such negotiations.

A staunch ideologue who has often rejected dialogue with America, Khamenei was apparently responding to a United States offer of one-on-one negotiations between the two countries on a range of topics, including Iran’s disputed nuclear program, a suggestion that Vice President Joe Biden reinforced last week during a security conference in Munich. The Iranian foreign minister said then he was open to such talks, although Biden noted that they could proceed only if the ayatollah showed serious interest.