China said on Monday it sought dialogue and peace for Ukraine despite US warnings that it might be considering weapons supplies for its ally Russia's invasion. Air raid sirens blared in the capital Kyiv and other cities overnight and a Russian missile killed one person in the western town of Khmelnitskyi, Mayor Oleksandr Symshyshyn said on the Telegram messaging app. The all-clear sounded after daybreak. China, which declared a "no limits" alliance with Russia shortly before the invasion a year ago, has refused to condemn the onslaught, most recently at a weekend meeting of the Group of Twenty (G20) major economies. On Friday, the first anniversary of the war, China published a 12-point plan calling for a ceasefire and gradual de-escalation by both sides, warning against the use of nuclear weapons and saying conflict benefited no one. Kyiv struck a receptive tone while reiterating there can be no peace without a total Russian withdrawal - a non-starter for Moscow - but Beijing's proposals cut little ice among Ukraine's NATO military alliance supporters. On Monday, China said it had kept contact with all sides in the crisis including Kyiv and its position was clear. "The core is to call for peace and promote dialogue and promote a political solution to the crisis," foreign ministry spokesperson Mao Ning told a news briefing in Beijing. NATO allies say they are trying to dissuade China from supplying lethal aid to Russia, possibly including drones. Moscow's forces are struggling to make gains in east Ukraine while Kyiv is eyeing a counter-offensive with advanced Western weapons, including battle tanks, pledged over the coming months. CIA Director William Burns said at the weekend the US intelligence agency believed Beijing was considering military aid to Russia though it had not reached a final decision. "If it goes down that road it will come at real costs to China," US National Security Adviser Jake Sullivan told CNN. Casting the Ukraine war as a battle for Russia's survival against a rapacious West, Russian President Vladimir Putin last week hailed "new frontiers" in ties with Beijing and indicated that his Chinese counterpart Xi Jinping would soon visit Moscow. "They have one goal: to disband the former Soviet Union and its fundamental part - the Russian Federation," Putin told Rossiya 1 state television. 'No fleeing' NATO and the West dismiss this narrative, saying their objective in supporting Kyiv is to help it repel an imperial-style land grab by Moscow, which has called its fellow former Soviet republic an artificial state. Putin's framing of the war as an existential threat to Russia accords him greater freedom in the types of weapons he could one day use, including possibly nuclear firepower. Dmitry Medvedev, Russia's former president and an ally of Putin, said in remarks published on Monday that the West's supply of arms to Kyiv risked a global nuclear catastrophe. A political adviser to Ukrainian President Volodymyr Zelenskiy dismissed Russia's version. "When the Russian Federation talks about a nuclear conflict... two questions arise," Mykailo Podolyak tweeted. "Why did you attack another country? Do you ask the world to give you the right to kill another country’s citizens with impunity, and if you’re beaten, you scream, 'Don't touch us'?!" Ukraine's outgunned and outnumbered but better organized and more nimble forces repelled Russia's attempt to seize Kyiv early in the war and later retook swathes of occupied territory in the east and south. But Moscow still controls nearly a fifth of Ukraine, which it claims to have annexed. On front lines, Ukrainian ground forces commander Colonel General Oleksandr Syrskyi visited Bakhmut, the bombed-out city in Donetsk province that has been the focus of a Russian artillery and infantry assault for months as Moscow tries to take full control of the eastern Donbas industrial region. In Luhansk province, the largely Russian-occupied northern half of the Donbas, Moscow has escalated shelling and infantry assaults in the embattled Bilohoryvka, Svatove-Kupiansk and Kreminna areas, Ukraine's Luhansk governor said on Monday. "There is no fleeing, our units do not leave territory. Moreover, there is success in certain sectors. They are advancing, they can de-occupy areas. Of course, everything can change at any moment," Serhiy Haidai told state television. "On the other hand, Western offensive heavy equipment is on the way and therefore in any week the military command can conduct an operation following the same plan as they did in the Kharkiv region." he said, referring to Ukraine's recapture of a northeastern sector from Russian forces last year.