Russian military forces will leave Belarus once joint exercises between the two ex-Soviet countries are over next month, the Belarusian Ministry of Defence said on Thursday.

The deployments to Belarus, north of Ukraine, are part of a wider Russian military buildup in the region that has stoked Western fears that Moscow is planning to attack Ukraine. Russia denies any such plan.

"At the end of the inspection, military units and sub-units of the Russian Federation's Armed Forces will leave the territory of the Republic of Belarus," the ministry said.

The Russian rouble, which has been under serious pressure during the Russian troop buildup, was up 1.1% on Thursday after the statement.

The Allied Resolve exercises are split into two phases and due to run until Feb. 20.