The Ukrainian Armed Forces are holding back the Russian advance in the Kharkiv Region, where the occupiers are likely to engage "African mercenaries".
This is stated in an analytical report by the Institute for the Study of War (ISW).
Kharkiv Region
Russian troops did not make any confirmed advance north of Kharkiv near Liptsy amid ongoing fighting on May 21.
The Russian milblogger claimed that Putin's troops had allegedly advanced 300 to 450 meters in the direction of Liptsy, but ISW did not see any visual evidence of this claim.
On the evening of May 21, the General Staff of the Armed Forces of Ukraine reported that the occupiers had significantly intensified hostilities in the Kharkiv direction after the number of Russian attacks had decreased on May 20.
The Russian invaders recently confirmed their advance southwest of Vovchansk. Geolocation footage released on May 18 shows that Russian troops have advanced further into Starytsia (southwest of Vovchansk).
The Russian Defense Ministry said that Russian troops had allegedly repelled Ukrainian counterattacks in Vovchansk and near Starytsia.
A Ukrainian serviceman operating in northern Kharkiv Region reported that Russian troops had deployed "African mercenaries" in the area and that the occupiers were conducting "meat assaults" with mercenaries before regular Russian forces attack.
Luhansk Region
Russian troops have recently confirmed advances along the Kupiansk-Svatove-Kreminna line. Geolocation footage released on May 21 shows that the occupiers have advanced southeast of Makiivka (northwest of Kreminna).
A Russian milblogger claimed that Russian troops had allegedly advanced 1 km near Makiivka. A Russian source claimed that Putin's troops had secured positions at a distance of 1.18 km along a forested area east of Stelmakhivka (northwest of Svatove).
The Russian invaders continued their offensive in the area of Synkivka, near Ivanivka, Berestove, Stelmakhivka, near Dibrova and Terny, near Hryhorivka and Bilohorivka.
Donetsk Region
Russian sources claimed that Russian troops had made marginal advances south of Siversk (northeast of Bakhmut), but the ISW did not observe visual evidence to confirm these claims.
Russian milbloggers said that unspecified elements of the Russian Airborne (VDV) Forces continued to attack in the Siversk direction and allegedly advanced north of Vesele (south of Siversk), but noted that the use of Ukrainian drones was complicating Russian advances in the area.
The General Staff of the Ukrainian Armed Forces reported that the occupiers attacked south of Siversk in the area of Rozdolivka and southeast of Siversk in the area of Vyimka.
Russian troops have recently advanced into southern and central Klishchiyivka (southeast of Chasiv Yar) and continued offensive operations at Chasiv Yar.
Southern Axis
On May 21, positional fighting continued in the west of Zaporizhzhia Region, but no confirmed changes to the front line were recorded in this area.
Ukraine's Southern Operational Command and Navy Spokesperson Captain Third Rank Dmytro Pletenchuk stated that Russian forces have not seized Robotyne.
Russian milbloggers claimed that Russian troops had allegedly advanced up to 3.5 km wide and 1 km deep southeast of Robotyne, although ISW did not observe visual evidence of this claim.
Positional fighting continued near Robotyne and Verbove.
On May 21, positional fighting continued on the eastern (left) bank of the Kherson Region, but no confirmed changes to the front line in the area were recorded.
Earlier, Apostrophe reported that Russians dropped four KAB bombs on Zolochiv, Kharkiv Region.