VIENNA>> Iran said it has built and will activate a third nuclear enrichment facility, ratcheting up tensions with the U.N. on Thursday immediately after its atomic watchdog agency censured Iran for failing to comply with nonproliferation obligations meant to prevent it from developing a nuclear weapon.

“The Islamic Republic of Iran has no choice but to respond to this political resolution,” the Iranian Foreign Ministry and Atomic Energy Organization said in a joint statement.

The censure by the International Atomic Energy Agency, its first in 20 years over Iranian non-compliance, could set in motion an effort to restore sanctions on Iran later this year.

U.S. President Donald Trump had previously warned that Israel or America could launch airstrikes against Iranian nuclear facilities if negotiators failed to reach a deal on Iran’s rapidly advancing nuclear program. A sixth round of Iran-U.S. talks is scheduled to begin Sunday in Oman, and as tensions simmer some American government staffers deemed nonessential have begun leaving the Gulf region.

Trump said Thursday he is still urging Iran to negotiate a deal, but that he is concerned a “massive conflict” could occur in the Middle East if it does not.

“I don’t want to say imminent, but it looks like it’s something that could very well happen,” Trump said in response to a question from a reporter about a potential Israeli attack. “Look, it’s very simple, not complicated. Iran cannot have a nuclear weapon.”

Trump offered guarded optimism that a conflict could still be avoided, and said he’s urging Israeli Prime Minister Benjamin Netanyahu to hold off from taking action for the time being.

“As long as I think there is a (chance for an) agreement, I don’t want them going in because I think it would blow it,” Trump said.

Trump said he felt it was necessary for his administration on Wednesday to direct a voluntary evacuation of nonessential personnel and their families from some U.S. diplomatic outposts in the Middle East.

“I don’t want to be the one that didn’t give any warning, and missiles are flying into their buildings. It’s possible. So I had to do it,” he said.

Nineteen countries on the IAEA’s board of governors voted for the resolution to censure Iran, according to diplomats who spoke on condition of anonymity to describe the outcome of the closed-doors vote.

The resolution was put forward by France, the United Kingdom, Germany and the U.S. Russia, China and Burkina Faso opposed it, while 11 abstained and two did not vote.

The resolution calls on Iran to provide answers “without delay” in a long-running investigation into traces of uranium found at several locations Tehran has failed to declare as nuclear sites, according to a draft seen by The AP.

Western officials suspect the uranium traces could provide further evidence that Iran had a secret nuclear weapons program until 2003.

Speaking to Iranian state television after the U.N. agency’s vote, the spokesman for the Atomic Energy Organization of Iran said that his agency immediately informed the IAEA of actions Tehran would take.

“One is the launch of a third secure site” for enrichment, spokesman Behrouz Kamalvandi said. He did not elaborate on the location, but the organization’s chief, Mohammad Eslami, later described the site as “already built, prepared, and located in a secure and invulnerable place.”

Another step would be replacing old centrifuges with advanced ones at an underground site at Fordo. “Our production of enriched materials will significantly increase,” Kamalvandi said.

Iran has two underground sites, at Fordo and Natanz, and it has been building tunnels in the mountains near Natanz since suspected Israeli sabotage attacks targeted that facility.

Iran said other measures were also being planned in response to the U.N. agency’s censure. The IAEA draft resolution said “Iran’s many failures to uphold its obligations since 2019 to provide the Agency with full and timely cooperation regarding undeclared nuclear material and activities at multiple undeclared locations in Iran ... constitutes non-compliance with its obligations.”

Under those obligations, which are part of the Nuclear Non-Proliferation Treaty, Iran is legally bound to declare all nuclear material and activities and allow IAEA inspectors to verify that none of it is being diverted from peaceful uses.

The IAEA’s draft resolution hints at reporting Iran to the U.N. Security Council to consider more sanctions, stressing that the global body is the “organ bearing the main responsibility for the maintenance of international peace and security.”