The attack caused fires at a large electronics plant in Mukachevo, with damage also reported in other cities, including Lviv, reported The Kyiv Independent.

Ukraine's Foreign Minister Andrii Sybiha confirmed the attacks on X and wrote: "Contrary to all efforts to end the war, Russia undertook a massive combined air strike on Ukraine overnight."

"Hundreds of drones, hypersonic, ballistic, and cruise missiles on civilian and energy infrastructure," he said.

"One of the missiles struck a major American electronics manufacturer in our westernmost region, leading to serious damage and casualties," he said.

He said it was a fully civilian facility that had nothing to do with defence or the military.

"This is not the first Russian attack on American businesses in Ukraine, after strikes on Boeing offices in Kyiv earlier this year and other attacks," he said.

Ukraine President Volodymyr Zelenskyy said: "In Mukachevo, the Russians practically burned down an American company producing electronics—home appliances, nothing military. The Russians knew exactly where they lobbed the missiles. We believe this was a deliberate attack against American property and investments in Ukraine."

The attack took place at a time when Zelenskyy met US President Donald Trump in Washington DC.

Stepping up efforts to end the war, Trump also met Russian President Vladimir Putin on 15 August in Alaska.

Nearly four years have passed since Russia launched its full-scale invasion of Ukraine, and more than 13,000 civilians have been killed, UN human rights monitors in the country have reported.