KYIV - As Kyiv's top general visited the frontline town of Bakhmut, where Ukrainian defenders were holding out against constant attacks, the US warned China of severe consequences if it provided arms to support Russia's invasion of Ukraine.

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

Western concerns about China assisting Russia in arming come as Moscow's forces struggle to gain ground around key objectives in eastern Ukraine, and Kyiv prepares a counter-offensive with advanced Western weapons such as 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, there will be real costs to China," White House national security adviser Jake Sullivan told CNN's "State of the Union" program.

Sullivan said in a separate interview on ABC's "This Week" that while China had not moved forward with providing that aid, it had also not ruled it out.

Beijing has consistently refused to condemn Moscow's attack on Ukraine, most recently at a Group of Twenty (G20) meeting in India on Saturday. On the first anniversary of Russia's invasion of Ukraine, it issued a cease-fire proposal, which was met with scepticism by Ukraine's Western allies.

"When I hear reports - and I don't know if they are true - that China may be planning to supply kamikaze drones to Russia while also presenting a peace plan, then I suggest we judge China by its actions, not its words," German Defence Minister Boris Pistorius said on Sunday to German public broadcaster Deutschlandfunk. In an interview aired on Sunday, CIA Director William Burns expressed confidence that the Chinese leadership is considering the provision of lethal equipment.

"We also don't see evidence of a final decision being made, and we don't see evidence of actual shipments of lethal equipment," Burns said on CBS's "Face the Nation" program.

According to McCaul, Chinese President Xi Jinping is planning a trip to Moscow next week to meet with Russian President Vladimir Putin.

Putin portrays the Ukraine war, which he refers to as a "special military operation," as a confrontation with the West that threatens Russia's and the Russian people's survival.

Nonetheless, Putin's framing of the war as a threat to Russia's existence gives the Kremlin chief greater leeway in the types of weapons he could use in the future, including 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.

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

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

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

He "listened to unit commanders dealing with urgent problems, assisted in their resolution, and supported the servicemen," the Ground Forces said on the Telegram messaging app.

Ukrainian President Volodymyr Zelenskiy fired a senior commander who was assisting in the fight in the east on Sunday but provided no explanation.

Zelenskiy announced the dismissal of Eduard Moskalyov as commander of Ukraine's joint forces fighting in the Donbas in a one-line decree.

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, a Russian ally and staging ground for Russian forces attacking Ukraine.