Russia said Sunday its forces had captured two frontline villages in Ukraine, Andriivka in the eastern Lugansk region and Pishchane in the northeast Kharkiv region.
Ukraine's President Volodomyr Zelensky welcomed the arrival of a Patriot air-defence system from Germany, as both sides announced more deaths from missile strikes.
Earlier Sunday, Russia said it had scrambled fighter jets to prevent two US strategic bombers from crossing its border over the Barents Sea in the Arctic.
The two villages Russia claims to have taken are less than 20 kilometres (12 miles) from each other on a section of the frontline where Moscow has made grinding advances in recent weeks.
Russian army units "liberated" the settlements of Andriivka and Pishchane "as well as occupied more favourable lines and positions," Russia's defence ministry said in a statement.
Andriivka, a village of less than 20 people, was one of the last settlements in the eastern Lugansk region that Kyiv still controlled and had been a key target for Moscow.
Pishchane has also been in the Kremlin's sights because its capture could pave the way for Russia to reach the Oskil river that lies about 10 kilometres away, according to the Institute for the Study of War.
Moscow claims to have taken a string of villages and settlements in recent weeks, many consisting of no more than a few streets and a handful of abandoned buildings.
Neither side has been able to achieve a decisive breakthrough and both Moscow and Kyiv say they are inflicting heavy casualties on the other, almost two and a half years after Russia launched its offensive.
In his evening address Sunday, Ukraine's President Volodymyr Zelensky said the country's air-defence systems had been reinforced.
"The German 'Patriot' system has arrived in Ukraine, and I would like to thank Germany and the United States for this step," he said. "We will be able to do more in the skies."
Zelensky has been pressing for the delivery of the 'Patriot' air-defence system for months.
Germany and Romania had already announced that they were sending their two Patriots and the Dutch have said they are working to put one together to help Kyiv. Italy is also providing a separate missile system.
Strikes on Sunday killed at least five civilians on both sides of the frontline, Russian and Ukrainian authorities said.
Four of the deaths occurred in three different Ukrainian artillery strikes in parts of the country now under Moscow's control, according to Russian-installed officials.
In an area controlled by Kyiv, a 37-year-old man was killed and his assistant injured by a Russian strike on a combine harvester, the Ukrainian prosecutor general's office said.
Earlier Sunday, the Russian defence ministry said its fighter jets had intercepted "a pair of US Air Force B-52H strategic bombers".
The US military routinely carries out flights over international waters, which it insists are in accordance with international law.
Moscow has responded more aggressively to the exercises in recent months. It said the two US bombers turned away from its border as the Russian fighters approached.
