Here's what we know about the new Ukrainian units.
TWELVE BRIGADESNATO allies and partners helped Ukraine equip and train nine new armoured brigades for the counteroffensive, the military alliance's Secretary General Jens Stoltenberg confirmed in April.
By April, Ukrainian units had received more than 1,550 armoured vehicles, 230 tanks, other equipment and vast amounts of ammunition, Stoltenberg said.
In mid-May, one Russian military blog noted a buildup of Ukrainian forces and equipment in southeastern Zaporizhzhia region and the neighbouring Dnipropetrovsk region, estimating Kyiv's troop numbers at 50,000-55,000.
ARE ANY OF THESE UNITS FIGHTING YET?
Persons:
Jens Stoltenberg, Stoltenberg, Ihor Klymenko, Kara Dag, Chervona, Valerii Markus, Jaeger, Tom Balmforth, Hugh Lawson
Organizations:
NATO, Steel, Hurricane, Reuters, Bradley, 35th Marine Brigade, Thomson
Locations:
Ukraine, U.S, Zaporizhzhia, Dnipropetrovsk, Azov, Crimea, Russia, Ukrainian