President of the European Commission, Ursula von der Leyen, appealed for an increase in military support in areas such as ammunition supplies.

“I think now is the time really to speed up and scale up the production of the standardised products that Ukraine needs desperately," she said. "For example, standardised ammunition. We cannot wait months and years until we are able to replenish (stocks) and until we are able to deliver that to Ukraine.”

Britain's Prime Minister, Rishi Sunak, also called for a 'doubling down' of military support to Ukraine, highlighting Britain’s recent commitment to provide battle tanks, advanced air defence systems and longer-range missiles to the country.

Sunak urged other nations to follow suit before Russia launches an expected spring offensive.

And Nato Secretary General Jens Stoltenberg said there was "no indication" that Vladimir Putin "has changed his ambitions".

At this critical juncture in the conflict, it is essential to "give Ukraine what it needs to win and survive as an independent sovereign nation in Europe," he said.

"The greatest risk of all is that Putin wins. If Putin wins in Ukraine, the message for him and other authoritarian leaders will be that they can use force to get what they want," he warned.

Meanwhile, the United States formally accused Russia of committing crimes against humanity in Ukraine. Vice President Kamala Harris said that the international community had both a moral and a strategic interest in pursuing those crimes.

“Russian forces have pursued a widespread and systemic attack against a civilian population - gruesome acts of murder, torture, rape, and deportation,” Harris explained.. She also cited “execution-style killings, beatings, and electrocution.”

On Friday, Moscow claimed a small gain in its grinding offensive, with mercenary group Wagner reporting the capture of a village near Bakhmut.