United Nations (UN) nuclear watchdog declared Iran in breach of its non-proliferation obligations. Iran quickly announced countermeasures in response to the decision.The International Atomic Energy Agency's (IAEA) Board of Governors made the declaration for the first time in almost 20 years. This means that the IAEA could report Iran to the UN Security Council..An IAEA official said Iran responded by informing the watchdog that it plans to open a third uranium enrichment plant. The move escalates tensions in an already volatile Middle East region.Meanwhile, US and Iranian officials will hold a sixth round of talks on Tehran's uranium enrichment programme in Oman on June 15. The Oman foreign minister confirmed the meeting..Security fears have risen since President Donald Trump said on Wednesday that American personnel were being moved out of the region. Trump warned it "could be a dangerous place" and said Tehran would not be allowed to develop a nuclear weapon.Trump has threatened to bomb Iran if nuclear talks fail. In a Wednesday interview, Trump said he had become less confident that Tehran would agree to stop enriching uranium..The decision comes at a sensitive time in the oil producing Middle East. Security has been destabilised by the effects from the Gaza war between Israel and Hamas that began in October 2023.Iran wants the US to lift sanctions imposed on the country since 2018. Iran has been in conflict with the IAEA ever since Trump withdrew the US from a nuclear deal during his first term..After the IAEA decision, Israel's Foreign Ministry said Tehran's actions undermine the global Non-Proliferation Treaty (NPT). It called Iran's behaviour an imminent threat to regional and international security.Iran is a signatory to the NPT, while Israel is not. Israel is the only nuclear power in the Middle East.