The movement of Russian military equipment had been observed in Belarus, "probably for regrouping units, as well as creating a reserve to replenish losses in manpower, weapons and equipment of groups operating in Ukraine," the statement said.

Read The threat at sea is the biggest, – Zelensky

Ukrainian forces had noted "frequent cases" of mines being laid in areas recently retaken by Russian forces in the Kyiv region, the statement added.

Some information: The United Kingdom Ministry of Defence said in an intelligence update Wednesday that some Russian units had returned to Belarus after suffering heavy battlefield losses in Ukraine. Belarus has been a base and staging area for Russian militar