Depleted uranium is a dense by-product left over when uranium is enriched for use in nuclear reactors or nuclear weapons.
The United States, Britain, Russia, China, France and Pakistan produce uranium weapons, which are not classified as nuclear weapons, according to the International Coalition to Ban Uranium Weapons.
Ingesting or inhaling quantities of uranium - even depleted uranium - is dangerous: it depresses renal function and raises the risk of developing a range of cancers.
"It's worth making sure everyone understands that just because the word uranium is in the title of depleted uranium munitions, they are not nuclear munitions, they are purely conventional munitions," Cleverly said.
A spokesperson from Britain's defence ministry said: "The British Army has used depleted uranium in its armour piercing shells for decades."