Fighting has intensified for Lysychansk, Ukraine's last big bastion in the strategic eastern province of Luhansk, and an adviser to President Volodymyr Zelenskiy concedes the city could fall

Russian forces seized Lysychansk's sister city Sievierodonetsk on the opposite side of the Siverskiy Donets river last month, after some of the heaviest fighting of the war.

A spokesman for the pro-Moscow self-styled Luhansk People's Republic,says Lysychansk has been brought under control, then added "Unfortunately, it is not yet liberated."

A Ukraine National Guard spokesman says the city remains in Ukrainian hands.