Britain's Foreign Secretary James Cleverly said on Wednesday there was no nuclear escalation in the Ukraine war after Russian President Vladimir Putin criticised Britain for supplying depleted uranium tank munitions to Ukrainian forces.
Britain had on Monday confirmed it was supplying Ukraine with ammunition which contained depleted uranium. The heavy metal is used in weapons because it can penetrate tanks and armour more easily due to its density, amongst other properties.
But Putin on Tuesday condemned British plans to send such ammunition to Ukraine, saying Moscow would be forced to respond accordingly as such weapons had "a nuclear component".
Cleverly said that Russia was the only country talking about mounting nuclear risks and the ammunition was conventional.
"There is no nuclear escalation. The only country in the world that is talking about nuclear issues is Russia. There is no threat to Russia, this is purely about helping Ukraine defend itself," Cleverly said at the launch of Britain's international technology strategy.
"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."
Britain has used depleted uranium in its armour piercing shells for decades and does not consider those rounds as having a nuclear capability. Russia is known to also have ammunition containing depleted uranium.
It is a particular health risk around impact sites, where dust can get into people's lungs and vital organs.
Russian Foreign Minister Sergei Lavrov said Britain was "taking this escalation to a new and very serious stage," while Russia's mission in Geneva accused London of prolonging the conflict and leaving "no chance for a political and diplomatic settlement of the Ukrainian crisis."
Belarusian President Alexander Lukashenko, a close Putin ally, also waded into the row on Wednesday, saying Russia would retaliate against the British decision by providing Belarus with ammunition containing "real uranium".
"We need to step back from this madness. As soon as this ammunition explodes on Russian troops' positions, you will see a fearful response, it will be a lesson for the whole planet," he told reporters in a video clip.
"Russia does not only have depleted uranium... We have to lower this trend towards escalation in the conflict and move towards a peaceful settlement."
(Additional reporting by Gareth Jones, Gabrielle Tetrault-Farber and Caleb Davis, writing by Sarah Young and Alistair Smout, editing by William James, William Maclean)
