Ukrainian President Volodymyr Zelensky claimed Russia has lost about 16,000 troops so far.

“The number of the Russian losses has exceeded 16,000 casualties,” in a video statement shared to social media on Friday, Zelensky said. “Among them are the high-ranking commanders. So far no reports of killed Russian general colonels or admirals. However, in that number we have a commander of one of the occupiers’ armies and a second in command of the Black Sea Navy.”

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During the first significant casualty update since March 2, the Russian Ministry of Defense announced in a briefing Friday that 1,351 military men had been killed in Ukraine and 3,825 had been injured.

Meanwhile, two senior NATO military sources assessed on Wednesday that between 7,000 and 15,000 Russian servicemen were killed in action in Ukraine, CNN reported. Other US sources have estimated Russian casualties in a similar range — between 7,000 and 14,000 Russian soldiers dead — but with “low confidence,” the report also stated.

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On Friday, former Ukrainian President Petro Poroshenko claimed that forces were able to secure 18 humanitarian corridors during the last week, rescuing 37,606 individuals, including 26,477 from the besieged city of Mariupol, who were transferred to Zaporizhzhia.

“All of these war crimes against the civilians in Mariupol and other cities of Ukraine will continue informing nations of the world,” Zelensky said.

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Earlier in the day, a top Russian general gave some of the most thorough public remarks on Russia’s military strategy in Ukraine to date, claiming that the “first stage” of their military campaign is now complete, with their primary focus now shifting to eastern Ukraine.

“In general, the main tasks of the first stage of the operation have been completed,” Colonel General Sergei Rudskoy, Russia’s first deputy chief of staff, declared during a briefing on Friday. “The combat potential of the armed forces of Ukraine has been significantly reduced, allowing us, I emphasize again, to focus the main efforts on achieving the main goal — the liberation of Donbas.”