Russia has denounced Washington’s plan to provide the Ukrainian military with ammunition containing depleted uranium as part of a new $1bn assistance package to Kyiv, describing the decision to provide the controversial arms as inhuman.

The Pentagon said on Wednesday that depleted uranium ammunition for US-made Abrams tanks would be part of a new military package worth up to $175m, out of more than $1bn in civilian and defence support that US Secretary of State Antony Blinken announced in the Ukrainian capital, Kyiv.

“The administration’s decision to supply weapons with depleted uranium is an indicator of inhumanity,” Russia’s embassy in Washington said on the Telegram messaging app following the announcement.

“Clearly, with its idea of inflicting a ‘strategic defeat’, Washington is prepared to fight not only to the last Ukrainian but also to do away with entire generations,” the embassy said.

“The US is deliberately transferring weapons with indiscriminate effects,” the embassy added.

“It is fully aware of the consequences: explosions of such munitions result in the formation of a moving radioactive cloud. Small particles of uranium settle in the respiratory tract, lungs, esophagus, accumulate in kidneys and liver, cause cancer and lead to the inhibition of the whole organism’s functions.”

Along with the depleted uranium shells for tanks that the US plans to deliver to Ukraine, the new military assistance package includes Javelin anti-tank missiles, tactical air navigation systems and additional ammunition for High Mobility Artillery Rocket Systems (HIMARS), according to the Pentagon.

While the United Kingdom sent depleted uranium munitions to Ukraine earlier this year, this will be the first US shipment to Ukraine of the controversial armour-piercing shells and it is set to stir controversy over the use of such weapons on the battlefield.

The US was widely criticised recently for sending cluster bombs to Ukraine, despite concerns over the dangers such weapons pose to civilians.

The use of depleted uranium shells is not banned under international law.

But their use has been fiercely debated, with opponents such as the International Coalition to Ban Uranium Weapons saying there are dangerous health risks from ingesting or inhaling depleted uranium dust, including cancers and birth defects.

Uranium is an extremely dense metal – about 1.7 times more dense than lead – and is so hard that it does not change shape when it hits a target. A by-product of uranium enrichment, depleted uranium ammunition can easily punch through armour plating and self-ignite in a searing cloud of dust and metal.

Not radioactive

US National Security Council spokesman John Kirby said on Wednesday that the ammunition is not radioactive and “not anywhere close to going into” the sphere of nuclear weaponry.

“This is a commonplace type of munition that is used particularly for its armour-piercing capabilities,” he said.

Following the UK’s provision of depleted uranium ammunition in March, Russian President Vladimir Putin warned that Moscow would “respond accordingly”, and accused the West of deploying weapons with a “nuclear component”.

Russian Foreign Minister Sergey Lavrov also said at the time that the munitions were “a step towards accelerating escalation”.

Putin announced that Russia would respond to the UK by stationing tactical nuclear weapons in neighbouring Belarus – the first outside Russia since the fall of the Soviet Union.

Blinken said on Wednesday that the latest assistance to Kyiv would ensure that Ukraine “has what it needs” to succeed in its ongoing counteroffensive against Russian forces, and also strengthen Ukraine’s longer-term defence capabilities.

“Certainly, we see the important progress that’s being made now in the counteroffensive, and that’s very, very encouraging,” Blinken told Ukraine’s President Volodymyr Zelenskyy in Kyiv.

The Institute for the Study of War, a Washington, DC-based think tank, said on Wednesday that Ukraine’s military continued to report advances against Russia’s front lines in the counteroffensive, particularly around the city of Bakhmut in the Donetsk region and Robotyne in the Zaporizhia region.