It is the Israeli government's first reaction to last week's telephone call between US President Barack Obama and Iranian President Hassan Rouhani, the first such phone call between US and Iranian presidents in three decades.
Mr Netanyahu is travelling to the US to meet with Mr Obama and to address the UN General Assembly which is meeting in New York.
The Israeli leader is sceptical about Mr Rouhani as Israel believes Iran is continuing to build nuclear weapons capability and that it threatens Israel.
Meanwhile, a senior Iranian politician says a single phone conversation between the US and Iranian presidents is not a sign that relations with Washington will be quickly restored.
The comments by Deputy Foreign Minister Abbas Araghchi appear aimed at calming Iranian hard-liners who oppose rapidly easing the 34-year diplomatic freeze with the US.
Some critics of Mr Rouhani shouted insults and hurled shoes at him - a huge insult in the Arab world - after his return from the annual UN gathering in New York, which included the groundbreaking 15-minute call with President Barack Obama.
Mr Araghchi was quoted by the Fars news agency yesterday as saying "normal relations" with Washington will need more than "a phone call, meeting or negotiations" - a reference to Iran's efforts to restart stalled talks over its nuclear programme.
The US and Iran broke ties after the 1979 Islamic Revolution and the siege at the US embassy in Tehran.