With large-scale Russian military exercises set to begin in Belarus, the US has ordered the departure of family members of US government employees, citing “an increase in unusual and concerning Russian military activity near the border with Ukraine”.

The decision comes just over a week after the state department pulled the families of American diplomats out of Ukraine in response to the build-up of Russian troops on the border. In a statement published Monday, the state department also warned US citizens planning travel to Belarus that “the situation is unpredictable”.

Although Russia insists that its military exercises pose no threat to Ukraine, which shares a 665-mile border with Belarus that is largely unguarded, the US has warned that they could be used as a pretext to prepare for a possible attack.

Ukraine’s capital, Kiev, is a short drive from Belarus’s southern border and is easily within range of the rocket systems Russia has deployed before the exercises.

Russia has deployed some of its most advanced and well-equipped forces to nine bases and airfields around Belarus, the Russian defence ministry says. Already, highly trained special forces units and airborne troops, together with powerful antiaircraft systems and hundreds of aircraft, have begun to arrive at bases around the country, Ukrainian and western officials say.

At least two Iskander-M rocket battalions have been sent to Belarus, equipped with rockets that can hit anywhere inside Ukraine, Konrad Muzyka, a Russian military analyst, said on Twitter.

The exercises, named Allied Resolve-2022, are unnerving not only for Ukraine, but also Nato countries. On Tuesday, Russia’s defence ministry published a video showing a Russian military field camp newly deployed on the border with Poland.