Sign up now for FREE unlimited access to Reuters.com Register April 18 (Reuters) – Russian forces launched a new offensive across much of eastern Ukraine on Monday and the “battle of Donbass” has now begun, Ukrainian President Volodymyr Zelensky and senior officials have said. The Ukrainian army has been preparing for a new Russian offensive on its eastern side since Moscow withdrew its forces near Kyiv and northern Ukraine late last month to focus on an attack on the Ukrainian region of Donbass. “We can now say that the Russian forces have started the battle of Donbas, for which they have been preparing for a long time,” Zelensky said in a video clip. Sign up now for FREE unlimited access to Reuters.com Register Secretary of the Security Council of Ukraine Oleksiy Danilov said in a televised comment: “These (Russian forces) have begun their efforts to begin the active phase this morning. “This morning, on almost the entire front line of the (eastern) Donetsk, Luhansk and Kharkiv regions, the occupiers tried to break through our defenses,” he said. Russia is concentrating its forces in eastern Ukraine using troops it has withdrawn from northern Ukraine and neighboring Belarus, a close ally of Russia. In a Facebook post, the command of the Ukrainian armed forces said that Russia’s main military force is focusing on controlling all of the Donetsk and Luhansk regions that make up the part of the land known as Donbass. “The second phase of the war has begun … Believe in our army, it is very strong,” wrote the chief of staff of the Ukrainian president, Andriy Yermak, in the Telegram messaging application. Russian aid has paved the way for a protracted battle that military analysts say is likely to inflict heavy casualties on both sides as Russians try to encircle Ukrainian fighter jets digging to defend the Donbas region. Sign up now for FREE unlimited access to Reuters.com Register Report by Maria Starkova in Lviv. curated by Jonathan Oatis and Sandra Maler Our role models: The Thomson Reuters Trust Principles.