(Corrects day of week in first paragraph to Saturday)
KYIV (Reuters) - Russia is sending a large number of reserve troops to Sievierodonetsk from other battle zones to try to gain full control of the frontline eastern city, the governor of Ukraine's Luhansk region said on Saturday.
"Today, tomorrow, or the day after tomorrow, they will throw in all the reserves they have ... because there are so many of them there already, they're at critical mass," Luhansk regional governor Serhiy Gaidai said on national television.
He said Russian forces already controlled most but not all of Sievierodonetsk.
(This story corrects day of week in first paragraph to Saturday)
(Reporting by Max Hunder; Writing by Alessandra Prentice; Editing by Timothy Heritage and Frances Kerry)
