A fresh confrontation between Tehran and the west is looming over Iran’s nuclear programme after the board of the UN nuclear watchdog voted heavily to censure the country for its repeated failure to cooperate with UN nuclear inspectors.

The vote by the IAEA (International Atomic Energy Agency) members was passed with 20 represented countries in favour, two against, and 12 abstentions. The two countries to vote against were Russia and China.

It came after the US dropped its objections to the censure and joined the European countries condemning Iran’s years-long failure to cooperate. The Biden administration had been reluctant to take the step, wishing not to open up another conflict with Iran in the Middle East, but the Europeans insisted the integrity of the nuclear non-proliferation treaty was at stake.

In backing the motion the US called for a longer-term strategy to be developed towards Iran’s nuclear programme, especially since many of the restrictions placed on Iran in the original 2015 nuclear deal will be lifted next year. The last censure motion against Iran 19 months ago led to Iran announcing that it was going to enrich uranium to 60% purity – close to weapons grade – at its Fordow fuel enrichment plant.

Iran signed a nuclear deal in 2015, the joint comprehensive plan of action (JCPoA) that saw western economic sanctions lifted in return for strong controls over its civil nuclear programme. But the country has gradually reduced inspectors’ access to its nuclear sites and also vastly increased its stock of highly enriched uranium in breach of the limits set. It says it did so in response to Donald Trump unilaterally pulling the US out of the agreement in 2018, a move that is widely seen to have undercut advocates of western engagement inside Iran.

Iran says a fatwa (Islamic edict or legal decree) forbids possession of nuclear weapons, and in recent days it has disowned remarks made by some senior politicians arguing Iran should develop a bomb.

In a joint statement to the IAEA board, the UK, France and Germany – the three European signatories to the agreement – said: “Iran now possesses 30 times the JCPoA limit of enriched uranium and its stockpile of high enriched uranium up to 60% has continued to grow significantly. Iran now has the approximate amount of nuclear material from which the possibility of manufacturing a nuclear explosive device cannot be excluded.”

It added: “The [International Atomic Energy] Agency has lost continuity of knowledge in relation to the production and inventory of centrifuges, rotors and bellows, heavy water and uranium ore concentrate.”

The IAEA director general, Rafael Grossi, had visited Iran before the quarterly board meeting in a bid to negotiate improved access, but the death of the Iranian president, Ebrahim Raisi, led to the discussions freezing.

In a joint statement issued before the vote, China, Iran and Russia called for fresh talks to revive the nuclear deal, saying it “was time for the western countries to show their political will, to refrain from the endless cycle of escalation that has been going on for almost the last two years. Passing of the resolution was a mistake that will only lead to confrontation.”

The Israeli foreign minister, Israel Katz, hailed the IAEA decision, saying: “This is the first resolution in 19 months on Iranian violations, paving the way for further actions against Iran’s nuclear activities … The free world must stop Iran now – before it’s too late.”

Iran’s specific countermeasures may be delayed by the country’s presidential election on 28 June, since candidates have different views on the wisdom of signing the deal in the first place.