Nuclear talks between Iran and world powers have only given the Islamic republic more time to pursue its quest for a nuclear weapon, a senior Israeli official told AFP on Saturday.
Two days of talks on Tehran's controversial atomic drive with the five permanent members of the UN Security Council -- the United States, China, Russia, Britain and France -- plus Germany ended on Wednesday.
The latest round of talks, in the Kazakh capital Almaty, were aimed at breaking the decades-old deadlock over Iran's atomic programme.
"We understand that the only thing that was achieved in these talks was to give Iran more time to move ahead in its quest for a nuclear weapon," the Israeli official said.
The official said that after the talks, US Under Secretary of State for Political Affairs Wendy Sherman arrived in Israel and briefed Israeli National Security Adviser Yaakov Amidror over the weekend.
The US State Department had on Wednesday called the talks "useful," while Israeli Prime Minister Benjamin Netanyahu warned that if Iran does not heed calls to halt its nuclear programme, it should face "a military sanction."
Israel and much of the West believes Iran's nuclear programme to be a cover for building an atomic weapons capability, a charge which Tehran strongly denies.
Netanyahu has repeatedly called for the world to lay down a clear red line for Iran which, if crossed, could spark harsh repercussions.
Israel, the Middle East's sole if undeclared nuclear power, believes Iran must be prevented from reaching a military nuclear capability at any cost, and has refused to rule out a preemptive military strike to stop it.