Ukrainian President Volodymyr Zelensky has said that hundreds of Chinese nationals were fighting at the Ukraine frontline alongside Russia, after accusing Moscow of dragging China into its invasion.
"As of now, we have information that at least several hundred Chinese nationals are fighting as part of Russia's occupation forces," Mr Zelensky told a gathering of military chiefs from allied countries in Brussels.
"This means Russia is clearly trying to prolong the war - even by using Chinese lives," he added.
Kyiv said this week that its forces had captured two Chinese nationals in the eastern Donetsk region fighting for Moscow, prompting allegations from Mr Zelensky that Russia was implicating Beijing in the invasion.
The Kremlin denied the claim, while China warned parties to the conflict against making "irresponsible remarks".
Mr Zelensky also issued a plea for more air defence systems, speaking via video from his hometown of Kryvyi Rig where a Russian ballistic missile last week killed 19 people, including nine children.
"You know that Ukraine has a shortage of air defence systems. You know that Patriot systems can effectively protect against ballistic threats," he said.
"I ask you to focus first of all on air defence for Ukraine. We truly need it. Ten Patriot systems -- the free world has them," he added.
The Ukrainian leader also called out Russia for having refused a complete ceasefire proposed by the United States with Ukrainian approval one month ago.
And he called on allies to make progress on creating a contingent of forces that could act as a deterrent against future Russian attacks after a halt to the fighting.
"We need to define clear details regarding the size, structure, deployment, logistics, sustainment, and the equipment and weapons of this security contingent in Ukraine," Mr Zelensky said.
Russia says it captures village in Ukraine's Sumy region
Meanwhile, Russia's defence ministry has said its forces had captured the village of Zhuravka in Ukraine's northern border region of Sumy, although Ukrainian officials made no acknowledgement that it had been taken.
Moscow has long staged air attacks on the region opposite Russia's region of Kursk, from which it is trying to evict remaining Ukrainian forces eight months after they launched a cross-border incursion and seized large chunks of territory.
Ukrainian officials said there was intensified Russian military activity on their side of the border, but gave no acknowledgement that Zhuravka had fallen into Russian hands.
Four days ago, Moscow said its forces had seized another village in the region, Basivka, a claim denied by Ukrainian officials.
The latest report by Russia's defence ministry made no further comment beyond saying its troops were in control of Zhuravka.
Russian state news agency Tass quoted security sources as saying the advance brought Russian forces closer to a third locality, Yunakivka, which it said served as a logistics hub serving Ukrainian forces fighting across the border in Kursk.
Sumy region governor Volodymyr Artiukh told regional defence officials that Russian attacks in the area had intensified 30% over the past week.
"Over the past seven days, the Russians have launched 47 assault operations on our defenders' positions," Mr Artiukh said in an account posted on Facebook.
"The enemy's main efforts are focused on the area around the settlements of Zhuravka and Vasivka," he added.
Mr Artiukh said Russian forces were still attacking civilian targets and infrastructure, with the latest assaults recorded on food industry sites, such as meat-packing plants and dairies.
He also said Russia remained focused on Ukrainian forces still holding territory in Kursk region, who were delivering "a worthy rebuff to the enemy and inflicting significant losses".
Russian President Vladimir Putin has repeatedly suggested that Russian forces carve out a buffer zone along the border.
On Tuesday, the Russian defence ministry released video of what it said was the recapture of the settlement of Guyevo, one of the Ukrainians' few remaining footholds in the Kursk region.
This week, Mr Zelensky acknowledged for the first time that Ukraine's forces were also active in Russia's Belgorod region, also on the border, in efforts to protect towns on the Ukrainian side.
