Russia is preparing to launch a major new offensive against Ukraine in the coming weeks, a top Ukrainian security official said, adding to mounting concerns in Kyiv and the West that the Kremlin is preparing a renewed push to seize large areas of the country.

“Russia is preparing for maximum escalation,” said Oleksiy Danilov, the secretary of Ukraine’s National Security and Defence Council, in an interview with Sky News published online early Wednesday local time. “It is gathering everything possible, doing drills and training.”