In an interview with Russia's Channel One, Russian Foreign Minister Sergey Lavrov said NATO weapons supplied to Ukraine are essentially a proxy war and that Russian troops will consider the Ukrainian warehouses storing the weapons as legitimate targets.

"Of course, these weapons will be a legitimate target for the Russian armed forces, which operate as part of a special armed operation. And warehouses, including in western Ukraine, have become such targets more than once," Lavrov said Monday. "If NATO, in fact, goes to war with Russia, through a proxy, and arms this proxy, then in war as in war."

Lavrov also claimed that "the real position of Ukraine is determined in Washington, London and other Western capitals."

"Therefore, our political analysts say, why talk with [Ukrainian President Volodymyr Zelenskyy]'s team, we need to talk with the Americans, negotiate with them, reach some kind of agreement," Lavrov said.

-ABC News' Natalia Shumskaia

Russian forces have carried out five strikes targeting Ukraine railway stations, according to the head of the state-run Ukrainian railways, Oleksandr Kamyshin.

The hardest hit were the towns of Zhmerynka and Kozyatyn, where five people were killed and 18 were injured, according to Serhii Borzov, the head of the Vinnytsia regional military administration.

No casualties were reported in the other railway strikes, which were in the Lviv, Rivne and Zhytomyr regions, officials said.

-ABC News' Natalya Kushnir, Fidel Pavlenko and Christine Theodorou

United Nations Secretary-General António Guterres is traveling on Monday to Moscow, where on Tuesday he will have a working meeting and lunch with Russian Foreign Minister Sergey Lavrov followed by a meeting with Russian President Vladimir Putin, a deputy spokesperson for the secretary-general said.

On Thursday, Guterres will visit Ukraine where he'll meet with Ukrainian President Volodymyr Zelenskyy and Ukrainian Foreign Minister Dmytro Kuleba.

-ABC News' Christine Theodorou

About 15,000 Russian troops have been killed since the Ukraine invasion began, British Defense Secretary Ben Wallace told Members of Parliament on Monday, according to the British Press Association.

Russia has lost more than 60 helicopters and fighter jets, and over 2,000 of Russia's armored vehicles have been destroyed or captured, Wallace added.

At least one person -- a journalist -- was killed in a rocket attack on a residential building in Kyiv on Thursday evening, ABC News has learned.

Kyiv Mayor Vitali Kilitschko said Friday that rescuers had found the body of a victim amid the rubble.

Radio Liberty, a service of the U.S.-funded Radio Free Europe/Radio Liberty, reported that one of its employees, Vira Gyrych, was killed when a Russian missile hit her apartment in the Ukrainian capital on Thursday. Her body was found beneath the wreckage Friday morning, according to the report.

Gyrych had worked as a journalist and producer for Radio Liberty's Kyiv bureau since 2018. Prior to that, she worked for leading Ukrainian television channels, according to Radio Liberty.

"The editorial staff of Radio Liberty expresses its condolences to the family of Vira Gyrych and will remember her as a bright and kind person, a true professional," Radio Liberty said in its report.

Israeli Ambassador to Ukraine Michael Brodsky also confirmed Gyrych's death in a Twitter post, saying she was a former employee of the Israeli embassy in Kyiv.

Thursday's rocket attack came as United Nations Secretary-General Antonio Guterres visited Kyiv. Five Russian missiles flew into the city, according to Ukrainian President Volodymyr Zelenskyy. At least 10 people were injured, including four who were hospitalized, according to the Kyiv City Council.