Portraying himself to be as tough as his domestic critics, President Hassan Rouhani of Iran criticized nuclear-armed powers on Wednesday, singling out the United States and Israel for what he described as false and hypocritical warnings about Iranian atomic ambitions.

In a speech, Mr. Rouhani repeated his government’s claim that it neither covets nuclear weapons nor aspires to have them. That is a central issue in the prolonged international negotiations over Iranian nuclear activities, which Iran asserts are for purely peaceful purposes.

“They tell us, ‘We don’t want Iran to make atomic bombs’ — you who have made atomic bombs,” Mr. Rouhani said sarcastically.

He also asserted that the nuclear weapons amassed by the United States and, he said, possessed by Israel, have done little to ease their worries about vulnerability to attack.