On 25th September 2009 the US, Britain, and France accused Iran of building a secret nuclear enrichment facility to create nuclear weapons.
Iran denied intending to create nuclear weapons, saying such was also prohibited under Islam. In 2015 The Iran Nuclear Deal was concluded between Iran and numerous countries including the US and Britain, which lifted sanctions and imposed limitations on Iran's nuclear activities.
In May 2018 the US withdrew from the deal.
Although President Donald Trump had criticized the deal for a long time, it is interesting that his announcement to withdraw came a few days after a public revelation from Israel, which claimed that its spies had stolen thousands of pages' worth of information from a secure building in Iran. The documents apparently contain extensive research and design information about nuclear bombmaking. The documents date back before 2015 but Israel contends that Iran tried to hide these documents from the world and didn't disclose how far advanced their research was during the negotiations of the 2015 Iran Nuclear Deal. Iran disputes the authenticity of the documents.