Russian forces have expanded offensive operations in Kharkiv Oblast, forcing Ukraine to deploy more reserve troops, Commander-in-Chief Oleksandr Syrskyi said on May 17.
In a post on Telegram, Syrski said Moscow's troops had failed to make a breakthrough but acknowledged there will be "tough battles ahead."
Moscow launched a new offensive with 30,000 troops on May 10, targeting Kharkiv Oblast, which is situated at the border with Russia in northeastern Ukraine.
Russian troops have focused their efforts in the directions of Lyptsi and Vovchansk, two settlements a few kilometers south of the border.
"The enemy expanded the zone of active hostilities by almost 70 kilometers, thus trying to force us to use an additional number of brigades from the reserve," Syrski said.
"The enemy launched an offensive well ahead of schedule when he noticed the rotation of our troops, however, he failed to break through our defenses.
"However, we understand that there will be tough battles ahead and the enemy is preparing for it."
Syrski's comments came a day after President Volodymyr Zelensky told journalists Russian troops were able to advance as far as 10 kilometers (6 miles) deep during their offensive in Kharkiv Oblast, but the front in the region has been stabilized.
Moscow's forces were halted by Ukraine's first line of defense, Zelensky said. They did not reach concrete fortifications, he added.
"The first and second lines are being built by the military, and the third line is built by local authorities. It is the most powerful... simply because it is further from (Russian) weapons, from shelling," Zelensky said.
"The deepest point of their advance is 10 kilometers. In some areas, there was no advance."
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