Russia assaulted cities and towns along a boomerang-shaped front hundreds of miles long and poured more troops into Ukraine on Tuesday in a potentially pivotal battle for control of the country's eastern industrial heartland of coal mines and factories.
If successful, the Russian offensive in what is known as the Donbas would essentially slice Ukraine in two and give President Vladimir Putin a badly needed victory after the failed attempt by Moscow's forces to storm the capital, Kyiv, and heavier-than-expected casualties nearly two months into the war.
The cities of Kharkiv and Kramatorsk came under deadly attack, and Russia also said it struck areas around Zaporizhzhia and Dnipro west of the Donbas with missiles.
Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said air-launched missiles destroyed 13 Ukrainian troop and weapons locations, while the air force struck 60 other Ukrainian military facilities, including missile warhead storage depots.
Russian artillery hit nearly 1,300 Ukrainian military facilities and over 1,200 troop concentrations over the past 24 hours, Konashenkov said. The claims could not be independently verified.
In what both sides described as a new phase of the war, the Russian assault began Monday along a front stretching more than 300 miles (480 kilometers) from northeastern Ukraine to the country’s southeast. Ukraine’s military said Russian forces tried to "break through our defenses along nearly the entire front line.”
A Russian victory in the Donbas would deprive Ukraine of the industrial assets concentrated there, including mines, metals plants and heavy-equipment factories.
A senior U.S. defense official, speaking on condition of anonymity to discuss the Pentagon’s assessments of the war, said the Russians had added two more combat units, known as battalion tactical groups, in Ukraine over the preceding 24 hours. That brought the total number of units in the country to 78, all of them the south and the east, up from 65 last week, the official said.
That would translate to about 55,000 to 62,000 troops, based on what the Pentagon said at the start of the war was the typical unit strength of 700 to 800 soldiers. But accurately determining Russia's fighting capacity at this stage is difficult.
A European official, likewise speaking on condition of anonymity to discuss military assessments, said Russia also has 10,000 to 20,000 foreign fighters in the Donbas. They are a mix of mercenaries from Russia's private Wagner Group and Russian proxy fighters from Syria and Libya, according to the official.
While Ukraine portrayed the attacks on Monday as the start of the long-feared offensive in the east, some observers noted that an escalation has been underway there for some time and questioned whether this was truly the start of a new offensive.
The U.S. official said that the offensive in the Donbas has begun in a limited way, mainly in an area southwest of the city of Donetsk and south of Izyum.