Nearly 8,000 migrants from the Middle East and North Africa transited Montenegro in 2019 en route to wealthier EU countries, nearly double the previous year's total, according to the International Organization for Migration.
"The army will be engaged to protect the state borders and assist law-enforcement agencies," the State Defence and Security Council said in a statement on Friday.
The deployment was expect to start by the end of the year.
The Balkan route for migrants heading for western Europe via Turkey, Greece and the countries of former Yugoslavia was shut down in 2016 by Ankara in return for EU aid and the promise of visa-free travel for its citizens.
Montenegro emerged as an alternative route for migrants traveling from Turkey via Greece and Albania, as well as for those stuck in Serbia.
Since the beginning of this year, Montenegrin police have broken up five migrant smuggling rings and arrested 51 suspected smugglers. Typically, they charge migrants several thousand euros to get them into the EU.