The Defense Ministry in Minsk announced that almost 9,000 Russian troops will be stationed in Belarus as part of a "regional grouping" of forces it claims are needed to protect its borders.
"The first troop trains with Russian servicemen who are part of the (regional grouping) began to arrive in Belarus," Valery Revenko, head of the Defense Ministry's international military cooperation department, wrote on Twitter.
He said the "the relocation will take several days," and involve "a little less than 9,000 people."
More information would be provided at a briefing for military attachés, he added.
Alyaksandr Lukashenka, the de facto leader of Belarus, said last week that his troops would deploy with Russian forces near the Ukrainian border, citing, without providing any proof, what he said were threats from Ukraine and the West.