As the UN, Iran and world powers triumphantly announced the implementation of the nuclear accord with Tehran and the removal of sanctions from the Islamic republic on Saturday, the mood in Jerusalem was far from celebratory.

Prime Minister Benjamin Netanyahu, in a statement issued immediately after the announcement was made, vowed that Israel “will monitor the implementation of the deal and will notify of any violation.”

He added that Tehran “has not abandoned its aspirations to acquire nuclear weapons, and continues to act to destabilize the Middle East and spread terrorism throughout the world.”

The premier, who has been perhaps the most vocal opponent to the deal on the global stage, called on world powers and on the International Atomic Energy Agency to “closely follow activities in Iran’s nuclear installations and at other sites to ensure that it does not continue to develop nuclear weapons covertly.”

He warned that “without an appropriate response to every violation, Iran will surmise that it can continue to develop nuclear weapons, to destabilize the region and to spread terrorism.”

Israel, he said, “will do everything it takes to maintain its security and defend itself.”

Minister of Public Security Gilad Erdan arrives to the weekly government meeting in Jerusalem, January 3, 2016. (Alex Kolomoisky/POOL)

Minister of Public Security Gilad Erdan arrives to the weekly government meeting in Jerusalem, January 3, 2016. (Alex Kolomoisky/POOL)

Earlier Strategic Affairs Minister Gilad Erdan warned that the implementation of the landmark nuclear deal between world powers and Iran would endanger the Middle East and fail to curb Tehran’s atomic program.

“The ‘implementation day’ of the nuclear agreement ushers us into a new and dangerous era, in which Iran is freed from most of its economic sanctions, without having to quit its nuclear program or provide explanations for its military activities,” Erdan said in a statement.

Erdan, who is also public security minister, said Iran continued to “supply arms to terror groups like Hezbollah and Hamas” while interfering in the internal affairs of Gulf States and violating a UN Security Council prohibition on “developing ballistic missiles.”

“This is a difficult day for all the states in the region that hoped Iran wouldn’t be able to obtain nuclear arms and would cease to meddle in the region,” said Erdan, who is close to Prime Minister Benjamin Netanyahu.

Israel tried to prevent the accord, arguing it would not stop Tehran from developing an atomic weapon if it wished. Iran has always denied seeking a nuclear bomb.

Netanyahu has called the deal a “historic mistake,” warning that it entrenches the Islamist regime in power, gives Iran tens of billions of dollars in sanctions relief to fund terrorism and promote regional instability, and paves Iran’s path to a nuclear arsenal.

An Israeli official said earlier Saturday that Iran’s first priority once the deal is implemented would be to spend its newly freed-up funds on military acquisitions, and not on civilian investments, Army Radio reported. Furthermore, the unnamed source said, the implementation of the agreement would have a direct impact on the region, as terror groups Hezbollah and Hamas — both recipients of Iranian largesse — would find themselves in possession of new and modern weaponry.

“The world powers are mistaken if they see Iran as a solution to regional stability, and not the source of the problem,” a second unnamed official said, according to the radio.