Iran has hit back at a US offer of negotiations, saying Washington had violated the terms of the 2015 nuclear accord. The US special envoy for Iran, Brian Hook, said on Wednesday that Washington now wanted to negotiate a treaty that included Tehrans ballistic missile program and its regional behavior. Hook said the new deal that Washington hoped to sign with Iran, would not be a "personal agreement between two governments like the last one, we seek a treaty." US President Donald Trump pulled out of the 2015 nuclear accord - which curbed Irans atomic activities in return for sanctions relief - in May, saying it did not go far enough. Iranian Foreign Minister Mohammad Javad Zarif took to Twitter on Thursday to dismiss the characterization of the last deal as a "personal agreement", saying it was "an intl accord enshrined in a UN (Security Council resolution)". "US has violated its treaty obligations too... Apparently, US only mocks calls for peace," he added in the message that was attached to a video of a protester who took to the stage after Hooks speech, shouting that sanctions were hurting Iranian people. Meanwhile, Iran asked the UN to condemn what it described as Israeli nuclear threats against it, while Israel said it was stepping up security around its atomic sites as a precaution against threats from Tehran and its regional allies. Israeli Prime Minister Benjamin Netanyahu used a visit to a secretive Israeli atomic reactor in August to warn the countrys enemies that it has the means to destroy them, in what appeared to be a reference to its assumed nuclear arsenal. "The United Nations members should not turn a blind eye to these threats and must take firms actions to eliminate all Israeli nuclear weapons," Irans ambassador to the United Nations, Gholamali Khoshrou said in letters to the UN Secretary General and the Security Council, according to Fars news agency. Khoshrou asked the United Nations to force Israel to join the Nuclear Non-Proliferation Treaty (NPT) and bring its nuclear program under supervision of the International Atomic Energy Agency (IAEA). The director general of Israels Atomic Energy Commission said on Tuesday that Iran and Syria posed significant proliferation threats to the region and called for UN action at the 62nd General Conference of the IAEA now taking place in Vienna. In a statement on Thursday, director general Zeev Snir said: "We cannot ignore the repeated and explicit threats, made by Iran and its proxies, to attack Israels nuclear sites. These outrageous threats, require Israel to take immediate action and continue to protect and defend its nuclear facilities." Israel, which is outside the NPT, neither confirms nor denies having a nuclear arsenal, a decades-old "ambiguity" policy. Netanyahu gave details in April of what he said was evidence of a secret Iranian nuclear weapons program. Iran called the documents fake. Snir said the IAEA must conduct a robust verification of Irans "clandestine activities" and also of an undeclared, secretive military nuclear reactor that he said Syria has built at Deir Ezzor.