TEHRAN, Young Journalists Club (YJC) - The bill describes the areas in the Donetsk and Luhansk regions as "temporarily occupied" by "aggressor country" Russia. It envisages the use of military force to get them back under Ukraine's control.
President Petro Poroshenko welcomed the new bill, saying it would help restore control of the east by "political and diplomatic means."
The conflict in the east erupted weeks after Russia's annexation of Crimea and killed more than 10,000 since April 2014.
A 2015 peace agreement helped reduce the scope of hostilities, but clashes have continued and attempts at a political settlement have stalled.
The bill, passed after raucous debate, contains no reference to the Minsk peace deal brokered by France and Germany that obliged Ukraine to pass legislation offering a broad autonomy to the separatist regions and a sweeping amnesty to the rebels. Most Ukrainian political forces have resented the idea.
"We can't make diplomatic and political agreements that are prone to change part of Ukraine's legislation," Ivan Vinnyk, a member of Poroshenko's faction in parliament, said while explaining why the Minsk deal wasn't mentioned.
The bill corroborates a ban on trade and transport blockade of the east that Ukraine introduced last year. Of all the documents issued by separatist authorities, Ukraine would only recognize birth and death certificates.
Alexander Zakharchenko, the chief rebel leader in the Donetsk region, criticized the new bill as a flagrant violation of the Minsk agreement signed by Ukraine and the rebels, saying it would encourage hawkish elements in Ukraine and fuel hostilities.
Volodymyr Fesenko, head of the Penta research center, an independent Kiev-based think-tank, said the main purpose of the bill is to defend Ukraine's interests in international courts.