The latest news of the war between Russia and Ukraine: live updates

After withdrawing from the areas around Kiev, Russian forces are repositioning to launch a new offensive on the Donbass region of eastern Ukraine.

Analysts say they will operate in familiar territory there, given the 2014 Russian invasion, and with shorter supply lines. The Russians would also be able to rely on an extensive network of trains to resupply their army – there is no such rail network for them north of Kyiv.

Ukraine’s leaders say they are also preparing for a major confrontation. Ukrainian Foreign Minister Dmytro Kuleba urged NATO leaders last week to send reinforcements. Western weapons have poured into Ukraine in recent days, but Kuleba said more is needed, and fast. He warned that the battle for eastern Ukraine “will remind you of World War II.”

The center of gravity appears to be located near the eastern city of Izyum, which Russian units captured last week while trying to link up with other forces in the Donbass region, in the southeastern part of Ukraine. The Russians are also trying to establish a land corridor between Donbass and Crimea on the Black Sea, which Russia invaded and annexed in 2014.

There are other indications that the two armies are preparing for a major battle. Newly released satellite imagery showed a Russian convoy of hundreds of vehicles moving south through the Ukrainian town of Veliky Prluk, east of Kharkiv and north of Izyum, according to Maxar Technologies, which published the images on Sunday.

“This will be a large-scale battle with hundreds of tanks and combat vehicles – it will be very brutal,” said Franz-Stephan Gade, a researcher at the International Institute for Strategic Studies in London. The scope of military operations will be fundamentally different from anything the region has seen before.

Since Russia’s annexation of Crimea, Moscow has supported separatist uprisings in two eastern provinces – Donetsk and Luhansk – in the Donbass. The conflict has claimed more than 14,000 lives over the past eight years.

“Russia is operating in very familiar territory,” said Ker Giles of Britain’s Conflict Studies think tank. He added that Russian forces “will have learned from their mistakes in the early days of the campaign against Ukraine.”

There is also an added benefit to Russia of railways in the east, Giles said, explaining that the networks there are dense and transnational already under Russian control.

However, despite all the supposed Russian advantages in the east, some analysts doubt that the army will be more effective in eastern Ukraine than in northern Kyiv. Western officials and analysts said the Russian forces that attacked the Ukrainian capital have been so badly damaged that many units are too exhausted to start fighting again. They also say that many Russian units appear to be in low morale, with some soldiers refusing to fight.

said Frederic W. Kagan, director of the Critical Threats Project at the American Enterprise Institute, who has partnered with the institute to study the war to track the war in Ukraine. The troops that are being deployed are being badly beaten and their morale seems low.”

Mr. Kagan said that Russian forces in the east may encounter some of the same mobility problems they experienced during their invasion of northern Ukraine. Russian troops were largely confined to the country’s roads, as they were unable to traverse the terrain. This left Russian armored vehicles and trucks vulnerable to attack from Ukrainian forces, who destroyed hundreds of Russian vehicles using anti-tank missiles supplied by the West.

For Russians, transportation problems are likely to get worse. Spring rain will turn much of the terrain into slush, further impeding movement.

Mr. Kagan noted that Russian forces “are significantly restricted by the roads, which may actually make the east more difficult because the road network is much worse than the network around Kyiv.”

Ultimately, Mr. Kagan said, both armies face severe challenges.

“The Russians have a lot of weight to carry, but they have a lot of problems,” Mr. Kagan said. “The Ukrainians have high morale and high motivation. And a lot of determination. But they are few in number and they do not have the infrastructure of a military state to support them.”

“In my opinion, this is neglect.”