The interim Ukrainian president reinstated military conscription Thursday in the face of an increasingly empowered pro-Russian separatist insurgency in the country’s eastern regions.

The measure follows a parliamentary vote on April 17 that recommended interim president Oleksandr Turchynov enact conscription “without delay,” AFP reports. The decision comes as thousands of Russian forces are amassed on the Russian-Ukrainian border.

Ukraine conscripted young men into the military until earlier this year, when former President Viktor Yanukovych, a Russian ally, scrapped the law. Yanukovych fled to Russia in February amid mass anti-government protests.

The office of the interim president posted to its website a statement that says, as translated by AFP, that conscription was being reinstated “given the deteriorating situation in the east and the south … the rising force of armed pro-Russian unites and the taking of public administration buildings … which threaten territorial integrity.”

Ukraine’s military has about 130,000 members, though reserves could boost that figure to roughly 1,000,000, according to the AFP.

Write to Noah Rayman at noah.rayman@time.com.