Russia launched its largest drone and missile salvo on Ukraine in more than a month, Ukrainian authorities said Thursday, as Moscow accused Kyiv of not being interested in a “sustainable, fair and long-term settlement.”

Nine civilians were killed in the strikes as well as in shelling in eastern Ukraine, officials said.

WATCH THE VIDEO ABOVE: Russia’s massive aerial assault on Ukraine continues.

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The attacks come just days after US President Donald Trump held a meeting with Russian leader Vladimir Putin in Alaska, followed by a White House summit with Zelensky and European leaders, in pursuit of an end to the conflict.

But since then, there have been few signs of tangible progress.

Russia’s foreign minister poured cold water on the idea of a leaders’ summit and security guarantees for Kyiv, saying the Kremlin won’t accept the placement of any foreign troops in Ukraine.

In its overnight attacks, Russia launched a total of 574 strike drones and 40 missiles on Ukraine, President Volodymyr Zelensky said Thursday, hitting as far west as the city of Lviv.

Missiles also struck an American-owned manufacturing company, Flex Ltd, in the western region of Zakarpattia, in an attack that injured at least 19 people, Ukrainian officials said.

Flex is a American-Singaporean company that provides electronics manufacturing services and is headquartered in Austin, Texas.

“Overnight, Russian missiles attacked one of the largest American investments in Ukraine – Flex – an active member of the American Chamber of Commerce,” said Andy Hunder, president of the American Chamber of Commerce in Ukraine.

“Russia continues to destroy and humiliate US businesses in Ukraine, targeting companies that invest and trade on the US stock markets.”

A spokesperson for Flex told CNN that six of its staff remain in hospital after the strike, and stressed that the company “does not produce, supply, or support any military equipment.”

Zelensky suggested Russia’s strike on Flex’s facilities was deliberate.

“The Russians knew exactly where they were hitting,” the Ukrainian leader said in his nightly video address.

“We believe that this was a deliberate strike against American property here in Ukraine, against American investments.”

The French Foreign Ministry condemned the massive attacks across Ukraine, saying they “illustrate Russia’s lack of willingness to seriously engage in peace talks.”

In a statement, Zelensky also noted the timing of Moscow’s strikes.

“The Russians carried out this attack as if nothing had changed at all. As if there were no efforts by the world to stop this war,” he said.

“A response is needed. There is still no signal from Moscow that they really intend to engage in meaningful negotiations and end this war.”

Zelensky said a day earlier he is ready to make “some compromise” on his demand that a ceasefire takes place before any talks with Russian President Vladimir Putin – as long as some security guarantees for Ukraine are established.

Ukraine and its allies in Europe have long pushed for there to be a ceasefire as a first step toward ending the war, which would require resolving seemingly intractable issues such as land and security guarantees.

But after Trump pivoted toward favoring a “peace deal” over an immediate ceasefire, Zelensky indicated he was willing to be flexible.

“The format that has been proposed likely involves some compromise,” he said.

“I told President Trump that, in any case, we will need a period of calm to develop the entire plan for ending the war – if we truly want the plan to be serious.”

Zelensky told journalists Wednesday that Ukraine is waiting for “security guarantees architecture” to be established within seven to 10 days before setting a date for talks with the Kremlin.

Kremlin pours cold water on bilateral meeting

Moscow’s comments, meanwhile, have openly contradicted the White House narrative that plans for a bilateral meeting between Putin and Zelensky are “underway.”

Russian Foreign Minister Sergey Lavrov reiterated Thursday the Kremlin is open in principle to a Putin-Zelensky meeting, but with an understanding that “all issues … will be worked out first” – effectively batting away plans for an imminent summit.

Lavrov also said that when it comes to signing a peace deal, “the issue of the legitimacy of the person who will sign future agreements on behalf of Ukraine will be resolved.”

The minister was referring to the Kremlin’s claim that Zelensky is an illegitimate president due to his term technically ending in May 2024, ignoring the fact that wartime conditions legally prohibit elections and allow him to remain in office.

He also warned against any deployment of foreign troops in Ukraine, calling it “absolutely unacceptable” for Russia and “all sensible political forces in Europe.”

Lavrov also tried to paint a picture that the Ukrainian side was impeding further talks.

Ukraine is “directly showing that they are not interested in a sustainable, fair and long-term settlement,” he said.

The Kremlin has said Putin proposed sending higher-level officials to talks with Ukraine in Istanbul, which, crucially, have so far included lower-level officials and have not made meaningful progress toward a ceasefire. In May, Putin decided not to show up for talks in Turkey that he himself suggested.

CNN’s Clare Sebastian, Pierre Bairin, Kristen Holmes and Betsy Klein contributed to this report.