A senior Israeli minister has criticised Binyamin Netanyahu's instruction to Israel's UN delegation to boycott the Iranian president's speech at the general assembly, saying it created the impression that Israel was not interested in encouraging a peaceful solution to Iran's suspected nuclear programme.

In a text message statement sent to reporters on Wednesday, the finance minister Yair Lapid described Netanyahu's instruction to Israeli delegates to leave during the speech as a mistake.

"Israel should not seem as if it is serially opposed to negotiations and as a country that is uninterested in peaceful solutions," said Lapid, whose centrist Yesh Atid party went into coalition with Netanyahu's Likud in March. "Leaving the UN general assembly and boycotting is irrelevant in current diplomacy, and is reminiscent of the way Arab countries have acted towards Israel."

Israel believes Iran is trying to develop a nuclear bomb, and Netanyahu has voiced scepticism at recent moderate gestures by the Iranian president, Hassan Rouhani, whom he has called "a wolf in sheep's clothing". Israeli officials fear Rouhani's outreach to the west could lead to an easing of international pressure on the country.

Netanyahu has explained why he instructed Israel's delegation to boycott Rouhani's speech.

"As the prime minister of Israel, the state of the Jewish people, I could not allow the Israeli delegation to be part of a cynical public relations ploy by a regime that denies the Holocaust and calls for our destruction," he said.

The Iranian leader said in his speech that he was ready to restart negotiations over his country's nuclear programme and called for moderation.

Netanyahu said Rouhani's address was filled with "hypocrisy" and that the world must keep up the pressure on Tehran.

An Israeli government official said Netanyahu believed optimism in the west about Iran's stated willingness to restart negotiations over its nuclear programme was similar to the euphoria expressed at the beginning of the wave of uprisings in Arab countries nearly three years ago.

"At the beginning of the Arab spring, Netanyahu said it could go in a good or a bad direction, and people accused him of being a dinosaur, accused him of ignoring the new hope. Of course those detractors now agree that his assessments are connected to reality," said the official, speaking on condition of anonymity because he was not authorised to speak about the matter to the media.

"He is not afraid to stand up to conventional wisdom when convinced that his assessment is correct," the official said. "He sees this as a moral obligation."