The exercise is the first of its kind in the country’s 30-year history as fears grow for spillover effects of US and NATO withdrawal from bordering Afghanistan.
Tajikistan held the largest military exercise in the country's history as the Taliban continue their sweeping advance in neighbouring Afghanistan.
The Central Asian nation mobilised 130,000 men from its military reserve in addition to 100,000 active servicemen for the three-hour exercise, President Emomali Rakhmon said on Thursday at a military parade later that day, urging vigilance amid fighting to the south of the border.
The 230,000 members of the security forces were alerted for the test on 2300GMT on Wednesday.
Rakhmon also said 20,000 troops has been redeployed to the Afghan border.
Show of force
The military drill was the first of its kind in the 30-year history of the former Soviet country and was broadcast on state television.
It involved testing of all weapons used by the Tajik army, including ground, aviation and artillery forces.
"Due to the unstable situation in the region I once again remind the people of Tajikistan that we must be ready to protect the peace and stability that have been achieved at a high price," Rakhmon said in his speech.
Russia, which operates a military base in Tajikistan, plans to hold joint drills there with Tajikistan and Uzbekistan, another of Afghanistan's neighbours, next month.
Taliban advances as foreign troops withdraw
The Taliban have gained control of large swaths of Afghanistan in recent weeks amid the ongoing withdrawal of US and NATO troops, two decades following the US-led invasion launched in the aftermath of the September 11 attacks.
The main Shir Khan Bandar border crossing with Tajikistan has also fallen under the group's control.
Tens of thousands of people have fled their homes across the country, with least 275,000 displaced inside Afghanistan, according to a UN count.
Hundreds of Afghan servicemen crossed the border into Tajikistan this month as they retreated from a Taliban offensive. Tajikistan later sent them back as the Kabul government arranged special flights to return its soldiers.