By Natalia Zinets and Max Hunder
-Russian forces are being pushed back around Kyiv but fighting is still fierce in some areas near Ukraine's capital, Ukrainian officials said on Friday.
Russia said during negotiations on Tuesday that it would scale down operations in the Kyiv and Chernihiv regions, both of which are in northern Ukraine, but officials in both regions say fighting has continued in some areas.
Reuters was unable to verify the information about military movements or fighting in Ukraine.
NATO Secretary-General Jens Stoltenberg has said Russian forces are not withdrawing but regrouping, and Ukrainian officials say Russian troops are losing ground rather than retreating of their own accord.
"Our troops are chasing them both to the northwest and northeast (of Kyiv), pushing the enemy away from Kyiv," said Oleksiy Arestovych, a political adviser to President Volodymyr Zelenskiy.
Arestovych said Russia was carrying out a partial troop rotation and sending some of its forces to fight in eastern Ukraine.
The Kyiv region's governor, Oleksandr Pavlyuk, wrote on the Telegram messaging app earlier on Friday that some Russian troops had moved back and were heading towards the border with Belarus, a Russian ally.
He said Russian forces had left the village of Hostomel, which is next to an important airport, but were digging in at the town of Bucha.
Mayor Vitaliy Klitschko later urged residents not to head back to Kyiv yet because "huge" battles were being fought to the north and east of the capital. He did not indicate that these were new battles.
"The risk of dying is pretty high, and that's why my advice to anyone who wants to come back is: Please, take a little bit more time," he said.
Chernihiv Governor Viacheslav Chaus said some Russian troops had pulled back but some remained in his region.
"Air and missile strikes are (still) possible in the region, nobody is ruling this out," he said in a video address.
Ukrainian officials also said the southern port city of Mariupol was still holding out after weeks of bombardment by Russian forces and that fighting continued in eastern Ukraine.