At least three people, including a pregnant woman, were killed in overnight Russian strikes on Ukraine, Kyiv said Tuesday, just hours after President Volodymyr Zelenskyy met with allies in London.

Ukraine said Russia was increasing its attacks on civilians as it was "unable" to achieve Kremlin-set aims in a fifth year of Moscow's invasion.

"At least three people were killed, including a pregnant 22-year-old woman, in Chuguiv," Foreign Minister Andriy Sybiga said, referring to a city in the northeastern Kharkiv region.

Emergency services published images of a blaze engulfing residential buildings and parked cars.

Chuguiv Mayor Galyna Minaeiva said the city – southwest of the regional capital Kharkiv – was hit by missiles and Iranian-made Shahed drones.

Russian progress on the sprawling front line has halted this year – despite Moscow recruiting up to 30,000 new fighters every month.

Both sides have escalated long-range drone strikes.

"Being unable to achieve its goals on the battlefield, Russia increases terror against civilians," Sybiga said.

"We urge the world to ramp up pressure on the Russian regime and further increase the cost of this terror for the aggressor."

Russian President Vladimir Putin last week rejected Zelenskyy's proposal for face-to-face talks to end the war.

Meeting in London over the weekend, Britain's Keir Starmer, France's Emmanuel Macron and Germany's Friedrich Merz said they supported Kyiv's proposal for "direct dialogue."

Zelenskyy told British media he had met with Russian oligarch Roman Abramovich in Kyiv, passing on a message to Putin that "we will not give you our territory."

The Russian leader has insisted Moscow intends to capture the whole of eastern Ukraine by force, however long it takes.

Russia's invasion of Ukraine has turned into Europe's worst conflict since World War II, with thousands of civilians and hundreds of thousands of troops killed.