Russian soldiers who desert, refuse to fight, disobey orders or surrender to the enemy now face up to 10 years in prison.
Putin signed the law on Saturday bringing tougher penalties for soldiers – which was approved earlier this week by the lower house of parliament.
Under the previous law, deserting soldiers faced five years in prison.
The disciplinary crackdown follows reports that some Russian soldiers in Ukraine have refused to fight, as well as reports of conscripts fleeing the country in an attempt to avoid being sent to the front line.
Russian President Vladimir Putin made the decision for partial mobilization to mobilize 300,000 reservists to fight in Ukraine.
