Russia is amassing vast numbers of troops and equipment along the northern frontline in Ukraine, Kyiv has warned.
Serhii Cherevatyi, spokesperson for the Eastern Group of Forces of the Armed Forces of Ukraine, told local television that Moscow had gathered more than 100,000 troops on the Lyman-Kupiansk axis, as well as 900 tanks, 555 artillery systems and 370 multiple rocket launchers.
The area, roughly between Kharkiv and Luhansk Oblast, is one of three sectors of the front in which Ukrainian forces have continued a counteroffensive, launched around June 4 with the aim of taking back Russian-occupied territory.
Kupiansk was liberated in Ukraine's counteroffensive in Kharkiv Oblast in September 2022. Lyman, in Donetsk Oblast, was recaptured weeks later.
Ukrainian media outlet Ukrinform said that the number of Russian troops that had gathered was not far off the 120,000 troops Moscow had deployed to Afghanistan during the height of the Soviet invasion there between 1979 and 1989.
"The enemy has gathered a very powerful group of forces," Cherevatyi, said, according to Ukrainian media outlets.
He said that in the northern axis, Russian forces had concentrated landing units, the best motorized infantry units, territorial troops and private military companies.
"They are concentrating everything in order to break through our defenses," he said, "Our soldiers are on the defensive. They don't allow the enemy to finally seize the initiative. That's why they hit them constantly."
He also said that Russia was facing losses of troops and weapons in the sector. This meant they needed to repair equipment and rotate personnel because, after announcing a major offensive in spring, Russian forces "want to show at least some success."
"That's why they concentrated their maximum efforts in this direction to show that they are capable of some offensive actions after the failure of the Bakhmut operation," added Cherevatyi, referring to the Donetsk town where he said Kyiv had "seized the initiative now."
The General Staff of the Armed Forces of Ukraine said that heavy battles are continuing as Moscow "continues to focus its main efforts on the Kupiansk, Lyman, Bakhmut, Avdiivka, and Marinka axes."
Meanwhile, the Institute for the Study of War (ISW) said on Monday that Russian forces had increased offensive operations in the Kupiansk area to exploit Ukraine's focus on other sectors.
It would also draw its reserves away from critical areas for their counteroffensive, such as Bakhmut, western Donetsk and western Zaporizhzhia oblasts.
However, the think tank said that "the poor quality and composition" of Russian troops in the area would "likely hinder Russia's ability to achieve more than tactically significant gains or make an operationally significant breakthrough."
Newsweek has emailed the Russian defense ministry for comment.
