The government has called up 1,684 reservists to a week-long "regular" training exercise, Okas 2021. It will include the construction of a "temporary border fence" of up to 40 kilometers.
On the proposal of the Commander of Estonian Defence Forces Martin Herem, 1,636 reservists mainly from engineer units will be included in the exercise which lasts from November 17-25.
The aim of Okas (which means "Quill") is to check the combat readiness of the national defense chain of command. This will be from government decision-making to the gathering of reservists in the rapid reaction structure.
Reservists will also construct temporary border fences in areas on the eastern border that have previously been used by organized crime to facilitate illegal migration.
Co-operation with the Police and Border Guard Board (PPA) will be practiced.
Elmar Vaher, director general of the PPA, said Estonia's security outlook has not changed and there is no immediate threat of migrants arriving on the border.
"What is happening in Poland, Lithuania and Latvia also requires the strengthening of border infrastructure in Estonia, which is why the PPA proposed to the government to speed up the construction of the border," he said.
"We are moving forward with the construction of the state border as a matter of urgency, as this is the most important effort to prevent mass immigration. Security experts say that migrant pressure will remain a hybrid warfare tactic for years."
On Monday, the government's security committee agreed to submit a proposal to the government for a temporary razor wire barrier on Estonia's eastern border.
Snap exercises have been carried out at least once a year since 2016.
Okas is being held against the backdrop of the migrant crisis on the Belarus-Poland border. There have been discussions in recent days about how Estonia could defend itself if migrants were to try and cross the border from Russia. It was said this would involve the construction of a temporary border fence.
Latvia is also holding military drills on its border with Belarus, public broadcaster LSM reported this week.
Estonian reservists whose units are involved in the exercise are required to immediately come to a meeting point outlined in the call-up. Reservists can check whether they are included in the additional training from the register of conscripts here.
Editor: Roberta Vaino, Helen Wright