Russia’s Defense ministry said on Saturday his country sent 12 armoured vehicles and an array of military equipment Tajikistan, as Moscow looks to shore up its Central Asian ally that neighbors Afghanistan.

Moscow has held military exercises in Tajikistan and expanded hardware at its military base there, its largest in a foreign country, since the U.S. withdrawal of troops from Afghanistan and the Taliban’s lightning takeover.

Russia is worried about the potential for fallout in the wider region and the possibility of Islamist militants infiltrating Central Asia, which Moscow sees as its southern defensive buffer.

“Against the backdrop of growing instability near Tajikistan’s southern border, we are working together to ensure the security of our states,” said Major General Yevgeny Tsindyaikin in a defence ministry statement.

The transfer of hardware, which also involves close combat equipment and protective gear, will modernize and significantly improve Tajikistan’s military capabilities, the ministry said.

Tajikistan’s border with Afghanistan stretches for 1,344 km (835 miles), and much of it is mountainous and hard to police.