Men between the ages of 18-60 are prohibited from leaving the country. Ukraine has been "left alone" to defend itself, President Volodymyr Zelenskyy has said.
Ukrainian President Volodymyr Zelenskyy signed a decree Thursday on the general mobilization of the population in the wake of Russia's invasion.
Conscripts and reservists will be called up over the next 90 days to "ensure the defense of the state, maintaining combat and mobilization readiness," an entry on the Ukrainian presidency's website said.
"We have been left alone to defend our state," Zelenskyy said in a video address to the nation after midnight.
"Who is ready to fight alongside us? I don't see anyone. Who is ready to give Ukraine a guarantee of NATO membership? Everyone is afraid," he added.