Iran's foreign minister said Thursday that the US and its ally Israel constitute a nuclear threat to the Middle East, on the 75th anniversary of the atomic attack on Hiroshima. 

"Today, US & Israeli nukes threaten our region," Mohammad Javad Zarif said on Twitter.

The first atomic bomb deployed in warfare was dropped on the western city of Hiroshima on August 6, 1945 by the US B-29 bomber Enola Gay, killing about 140,000 people. 

"75 years ago today, the US gained the infamy of becoming the 1st and ONLY user of nuclear weapons. And against innocents," Zarif said. 

Israel is believed to be the Middle East's sole nuclear-armed power, though it has never acknowledged it.

Zarif's words come in a context of tensions between Tehran and Washington, which unilaterally pulled out of a multilateral nuclear deal with Iran in 2018 and reimposed sanctions. 

The US and Israel accuse Iran of being set on developing a nuclear bomb, a charge always denied by Tehran. 

Iran and the US came to the brink of direct confrontation in January, when a US drone strike killed top Iranian general Qasem Soleimani in Iraq.

"It's long overdue to end the nuclear nightmare & the MAD doctrine of Mutually Assured Destruction," Zarif added, alluding to a Cold War theory that the threat of a nuclear holocaust generates a disincentive for two nuclear armed powers to go to war.

Washington and Tehran have had no formal diplomatic relations since 1980.