Ukrainian President Volodymyr Zelensky asked South Korean lawmakers Monday for arms and equipment to help it fight Russia, which he said was amassing "tens of thousands" of troops for a new offensive in eastern Ukraine, according to the Washington Post.

Why it matters: With Russia's invasion stymied in Ukraine's north, it has turned its attention to Ukraine's Donbas region, as indicated by newly released satellite images showing an eight-mile-long Russian military convoy comprised of armored vehicles and trucks moving in that direction.

• It's unclear when exactly Russia will let loose this next offensive, but the Kremlin may be planning for a victory in the region by May 9, which is the country's annual Victory Day celebration of the Soviet Union's World War II victory over the Nazis.

What they're saying: “The Republic of Korea has tanks, ships and various equipment that can block Russian missiles and we would be grateful if the Republic of Korea could help us fight back against Russia,” Zelensky said, using South Korea’s formal name, according to .

• “If Ukraine is able to receive such weapons, it will not only help us save the lives of our ordinary citizens but also provide Ukraine an opportunity to survive as a nation, and also help prevent other countries from being attacked by Russia,” he added.
• “Russia doesn’t care how many people die."

The big picture: Zelensky said there "are tens of thousands of dead” in Mariupol, a city once home to almost 500,000 that has been besieged by Russian troops since early March.

• “The worst situation is in Mariupol, in our southern port city, which has been blockaded by Russian troops since March 1," he said, according to the Financial Times. “It was a city of half a million. Mariupol is destroyed."
• At least 300 people were killed by a Russian airstrike on a theater in Mariupol, where Russian forces also struck an art school, a mosque and a children's hospital and other civilian buildings.

Go deeper: Ukraine has opened 5,600 war crimes cases, official says