Iran appears to have followed through on its vow to increase enrichment after a bomb attack on its nuclear facility in Natanz.
Iran has started enriching uranium up to its highest level ever, according to the country's parliament speaker, bringing it closer to a level considered weapons-grade.
State television quoted speaker Mohammad Bagher Qalibaf making the announcement on Friday, who said uranium is being enriched up to 60% purity. He did not elaborate on how much would be enriched to this level.
To put this into perspective, the landmark nuclear treaty signed by Iran in 2015 limited enrichment to 3.67%. Iran later raised this to 20%, breaching the deal, after the US unilaterally pulled out under Donald Trump's administration.
Therefore, 60% is a much higher level than agreed; although, still less than the weapons-grade level at 90%.
The move comes in response to an unexplained attack on its Natanz nuclear site last weekend, which is said to have damaged a number of centrifuges.
While the attack has not yet been claimed, it is widely suspected to have been carried out by Israel - a country that has vowed never to allow Iran to obtain a nuclear weapon and has twice previously carried out pre-emptive bombings in Middle Eastern countries to thwart atomic programmes.
The attack has since marked a significant escalation in tension, despite talks underway in Vienna in an attempt to save the flailing nuclear agreement. It is hoped the US will re-join the agreement and lift stifling economic sanctions that were in place by Trump.
According to Iranian officials, its domestic nuclear programme is peaceful. A US intelligence report released on Tuesday also said its assessment deemed Iran was "not currently undertaking the key nuclear weapons-development activities that we judge would be necessary to produce a nuclear device".
Iran previously had said it could use uranium enriched up to 60% for nuclear-powered ships. However, the Islamic Republic currently has no such ships in its navy.