Ukrainian President Volodymyr Zelenskyy has warned that Russian President Vladimir Putin is preparing to escalate the war, calling on the country's partners to ramp up sanctions pressure on Moscow and provide Kyiv with further air defense support.

His comments come shortly after deadly Russian attacks across Ukraine overnight. At the same time, Ukraine continues to launch long-range drone strikes deep into Russian territory, targeting the likes of Amazon-style retail giant Wildberries.

In a post on social media on Tuesday, Zelenskyy said emergency response efforts had been ongoing in Zaporizhzhia after the city was struck with North Korean ballistic missiles on Monday evening.

Ukraine's president described the strike as a "vicious attack" that killed six people and injured 19. Separate attacks were also reported in Kyiv and in Dnipropetrovsk overnight, killing at least three people.

"Every step Russia takes – increasing ballistic missile production, bringing in North Korean equipment, preparing for mobilization – all of this shows that Moscow is preparing not for peace, but for escalation. And the world needs to respond now, not wait," Zelenskyy said via X.

"More sanctions pressure specifically on enterprises that fuel Russia's war, more air defense assistance for Ukraine – all of this is needed to give peace a chance. I am grateful to everyone who is helping," he added.

Russian forces have increased the number of missile strikes on Ukrainian cities in recent weeks, likely as part of a push to exploit Kyiv's shortage of ballistic missile interceptors.

Ukraine remains heavily reliant on the American Patriot PAC-3 system to intercept Russian ballistic missiles, even as domestic companies such as Fire Point scramble to procure their own antimissile technology.

Zelenskyy has repeatedly called on international partners to expedite the supply of ballistic missile interceptors to Ukraine, saying that the technology could have saved the lives of those killed in Kyiv on Aug. 5.

U.S. President Donald Trump cast doubt last month on whether Washington would allow Kyiv to manufacture Patriots domestically and in Europe.

The apparent backtrack has raised alarm among Ukrainian officials who fear a winter assault could pose the country's toughest challenge of the war yet.