Iran nuclear crisis in 300 words
A landmark nuclear deal between Iran and world powers is facing one of its toughest tests since it came into effect in 2015. Here's how it got to this point.
What does the deal do?
Iran has always insisted its nuclear programme is peaceful.
But suspicions it was being used as a cover to develop a nuclear bomb prompted the UN Security Council, US and EU to impose crippling sanctions on the country from 2010.
Four years ago, Iran reached a deal with six powers - the US, UK, France, China, Russia and Germany - that saw it limit its nuclear activities in return for sanctions relief.
The deal restricted Iran's enrichment of uranium, which is used to make reactor fuel but also nuclear weapons. It was also required to redesign a heavy-water reactor being built, whose spent fuel would contain plutonium suitable for a bomb, and allow international inspections.
What prompted the latest crisis?
President Donald Trump unilaterally withdrew from the deal in May 2018 and reinstated US sanctions. He said he wanted a new deal that would also curb Iran's ballistic missile programme and its involvement in regional conflicts.
Iran refused and saw the value of its currency plummet and its inflation rate soar as the sanctions targeting its oil and financial sectors took effect.
When Mr Trump tightened the sanctions this May, Iran responded by suspending some commitments enshrined in the deal.
What has Iran done?
On 1 July, Iranian media reported a 300kg (660lb) limit on its stockpile of enriched uranium had been exceeded.
Iran has also given European powers until 7 July to shield its economy from the sanctions' effects. If they fail, it may abandon other restrictions and halt the redesign of its heavy-water reactor.
The Europeans have warned there will be consequences if any breach of the deal is confirmed by the International Atomic Energy Agency. They would be able to quickly "snap back" UN and multilateral sanctions.