KYIV — Russia is intensifying its attacks in Ukraine’s northeastern Kharkiv region as it aims to retake territory which it lost during Ukraine’s stunning counteroffensive last fall.

With Ukraine now pushing on the southern front, where Kyiv has liberated settlements and destroyed Russian logistics, the Kremlin’s invading forces are heavily targeting Kupiansk, an important logistics hub in the Kharkiv region.

The renewed Russian offensive comes as fighting in Ukraine’s east is heavily bogged down in a war of attrition, with both sides struggling to make big gains. Ukraine’s counteroffensives faces heavily fortified Russian positions, as Moscow’s forces learn lessons from a total wipeout last September when Ukraine stormed the Kharkiv region. And amid the grinding stalemate in the south and east, the Kremlin’s troops are pivoting to a major assault in the northeast.

“Russians are aiming to retake the Kharkiv region to take revenge for their loss there last year,” Serhii Cherevatyi, spokesman for Ukraine’s Armed Forces Command East told POLITICO. “But we’re ready, we know their plans, we have built a strong defense line. Plus, there Russians will face an army under the command of one of the most experienced Ukrainian generals — Sirskiy.”

Ukraine Land Forces Commander General Oleksandr Sirskiy was behind last year’s rapid Ukrainian success in the Kharkiv region, where it pushed Russian occupiers out in a lightning counterattack. The Russian front collapsed within days, and towns including Kupiansk came back under Ukrainian control.

But in the last 24 hours Russia has conducted 16 airstrikes and shelled Ukrainian positions 559 times on the northeastern front, Cherevatyi said. The Russians attacked four settlements in the Kharkiv region, two villages in the nearby Luhansk region and three in the Donetsk region. “The enemy also tried to storm the positions of the defense forces. Three attacks took place in the Kupiansk direction,” he added.

Intensified Russian shelling forced Kharkiv regional authorities to consider evacuating more than 11,000 people from 53 settlements on the front line, said Oleh Synegubov, Kharkiv regional governor. In the last day, Russia has massively bombarded populated areas of Bohodukhiv, Kharkiv, Chuhuiv, Izyum, and Kupiansk districts using guided air bombs and other weapons.

So far, Synegubov added, the Russian attacks have not yielded any success in the Kharkiv region.