The United States warned China of serious consequences if it provided arms to support Russia's invasion of Ukraine, as Kyiv's top general visited the frontline town of Bakhmut where Ukrainian defenders were holding out against constant attacks.

Washington and its NATO allies are scrambling to dissuade China from providing military aid for Moscow's war, making public comments on their belief that Beijing is considering providing lethal equipment possibly including drones.

Western fears of China helping to arm Russia come as Moscow's forces struggle to make gains around key objectives in eastern Ukraine, and as Kyiv prepares a counter-offensive with advanced Western weapons including battle tanks.

"Beijing will have to make its own decisions about how it proceeds, whether it provides military assistance - but if it goes down that road it will come at real costs to China," White House national security adviser Jake Sullivan told CNN's "State of the Union" programme.

While China had not moved forward in providing that aid, neither had it taken the option off the table, Sullivan said in a separate interview on ABC's "This Week" programme.

Beijing has refused to condemn Moscow's attack on Ukraine, most recently at a meeting of the Group of Twenty (G20) in India on Saturday. It published a ceasefire proposal on Friday, the first anniversary of Russia's invasion of Ukraine, but the offer was met with skepticism among Ukraine's Western allies.

"When I hear reports - and I don't know whether they are true - according to which China may be planning to supply kamikaze drones to Russia while at the same time presenting a peace plan, then I suggest we judge China by its actions and not its words," German Defence Minister Boris Pistorius told German public broadcaster Deutschlandfunk on Sunday.

CIA Director William Burns also weighed in regarding China in an interview aired on Sunday, saying the U.S. Intelligence agency was "confident that the Chinese leadership is considering the provision of lethal equipment".

"We also don't see that a final decision has been made yet, and we don't see evidence of actual shipments of lethal equipment," Burns told CBS's "Face the Nation" programme.

Republican Representative Michael McCaul, chairman of the U.S. House of Representatives Foreign Affairs Committee, cited reports that drones were among the weapons China was considering sending to Russia.

McCaul said Chinese leader Xi Jinping was preparing to visit Moscow next week for a meeting with Russian President Vladimir Putin.

Putin cast the Ukraine war, which he calls a "special military operation", as a confrontation with the West which threatens the survival of Russia and the Russian people.

"They have one goal: to disband the former Soviet Union and its fundamental part - the Russian Federation," Putin told Rossiya 1 state television in an interview recorded on Wednesday but released on Sunday.

NATO and the West dismiss this narrative, saying their objective in providing weapons and other aid to Kyiv is to help Ukraine defend itself against an unprovoked attack.

Even so, Putin's framing of the war as a threat to Russia's existence allows the Kremlin chief greater freedom in the types of weapons he could one day use, including possibly nuclear weapons.

Dmitry Medvedev, Russia's former president and an ally of Putin, said in remarks published on Monday that the supply of Western arms to Kyiv risked a global nuclear catastrophe.

On the frontlines, Ukrainian ground forces commander Colonel General Oleksandr Syrskyi visited the eastern city of Bakhmut, the focus of Russia's attacks for months as it tries to take control of the Donbas industrial region.

Ukrainian forces launched a number of counter-attacks and repulsed Russian forces around the village of Yahidne over the weekend, after Russia's Wagner mercenary group claimed to have captured it and the village of Berkhivka.

The Russian defence ministry said on Sunday that its forces had destroyed Ukrainian "sabotage and reconnaissance groups," including in the area of Yahidne, while Russia's TASS state agency reported that Ukraine's forces blew up a dam just north of Bakhmut.

Reuters was unable to independently verify the reports.

Syrskyi visited Bakhmut to boost morale and talk strategy with units defending the town and surrounding villages, the Ukrainian military said.

He "listened to the unit commanders tackling urgent problems, provided assistance in solving them, and supported the servicemen," the Ground Forces said on the Telegram messaging app.

Ukrainian President Volodymyr Zelenskiy on Sunday fired a senior commander helping lead the fight in the east, but gave no reason for the move.

In a one-line decree, Zelenskiy announced the dismissal of Eduard Moskalyov as commander of the joint forces of Ukraine, which are engaged in battles in the Donbas.

In neighbouring Belarus, a Russian ally and staging ground for Russian forces attacking Ukraine, Belarus partisans and members of the exiled opposition said they damaged a Russian A-50 surveillance military aircraft in a drone attack near Minsk on Sunday.

Reuters was unable to independently verify the reports. There was no immediate response from the defence ministries of Russia and Belarus to a request for comment.

(Reuters)

U.S. warns China against providing lethal aid for Russia's war in Ukraine