Iran will begin enriching uranium to 60 per cent purity, higher than the programme ever has before though still short of weapons grade, after an attack on its Natanz nuclear facility, an Iranian negotiator said on Tuesday.

The announcement marks a significant escalation after the sabotage, suspected to have been carried out by Israel. It could result in further action by Israel, whose Prime Minister Benjamin Netanyahu has vowed never to allow Tehran to obtain a nuclear weapon, and further raise tensions across West Asia.

Nuclear negotiator Abbas Araghchi’s comment, quoted by the state-run Irna news agency, came after Iran’s foreign minister warned that the weekend assault could hurt ongoing negotiations over its tattered atomic deal with world powers.

Those talks are aimed at finding a way for the US to re-enter the agreement, the goal of which is to limit Iran’s enrichment of uranium in exchange relief on sanctions.

Iran had been enriching up to 20 per cent. That is a short technical step to weapons-grade levels of 90 per cent.

The International Atomic Energy Agency said it was aware of the media reports but had no comment at the time.

Press TV, the Iranian state television’s English-language arm, separately said that the IAEA had been informed of the move. It said the enrichment would begin from Wednesday.

Iran’s Supreme Leader Ayatollah Ali Khamenei had threatened to go to 60 per cent enrichment in February if the country needed. “We are determined to develop our nuclear capabilities in line with the needs of the country,” Khamenei said then, according to a transcript of his speech.