Russian President Vladimir Putin on Wednesday signed a decree to expedite applications for Russian citizenship by Ukrainians living in separatist-held areas, a move that could shatter hopes for peace in the region following the election of a new Ukrainian president.

The decree published on the Kremlin's website says people living in the parts of Ukraine's Donetsk and Luhansk regions under separatist control will have their applications considered in under three months. They will have to swear allegiance to Russia when given Russian citizenship.

Putin's decision could trigger a major escalation in the war in the East and dampen chances for a peace process in the region that seemed to have appeared after the election of a new Ukrainian president, Volodymyr Zelenskiy.

Zelenskiy's office said in a statement that the move confirms Russia's role as an "aggressor state" in the conflict in the East, and added it "does not bring us closer to the main goal of stopping the war."

Outgoing President Petro Poroshenko called Putin's decree "yet another unprecedented act of Russian interference in Ukrainian affairs" and accused Moscow of undermining the peace process. Foreign Affairs Minister Pavlo Klimkin earlier on Wednesday called on Ukrainians in the separatist-controlled territories to "refuse Russian passports."

Only holders of ID cards issued by separatist authorities will be eligible for the expedited procedure offered by Putin. Separatist authorities said Wednesday that they had issued about 300,000 such ID cards in the area with an estimated population of 3.7 million.

Putin insists he's not interfering

Commenting on the citizenship decree at a meeting with lawmakers in St. Petersburg, Putin said his order was not intended to "create problems for the new Ukrainian administration." He said he signed the decree for "humanitarian" reasons, claiming people in Donetsk and Luhansk are suffering and "have no civil rights left."

Putin did not explain why he didn't offer expedited citizenship for Donbass residents earlier despite insistent calls from Russian nationalists. The Kremlin did not act on the calls, even during the worst fighting in a conflict that has claimed more than 15,000 lives.

Ukraine’s newly elected president Volodymyr Zelenskiy is a political rookie who ran a campaign without a lot of concrete promises leaving many unsure what to expect. 2:07

Speculations about expedited citizenship for the Donetsk and Luhansk regions were swirling in Russia throughout the Ukrainian presidential campaign, but it had appeared that the Kremlin was only intending to go through with it if Poroshenko had won.

On Sunday, Poroshenko was easily defeated in a runoff by comic actor Zelenskiy, who will be sworn in next month. Zelenskiy has said his priority for the presidency is to end the war in the east that has claimed more than 15,000 lives.

In his presidential campaign, Zelenskiy did not sound as bellicose as his predecessor and spoke for a peaceful resolution of the conflict.

Putin, however, unlike other world leaders, has not yet congratulated him on his victory, saying the election results are not yet final.

After annexing Crimea in a hastily called referendum, Russia threw its weight behind separatist rebels in the east but stopped short of recognizing their independence vote or, until now, offering Russian citizenship to the local residents, even during the worst of fighting.

Ukraine and almost all the world views Russia's annexation of Crimea as illegal.

Volodymyr Yelchenko, Ukraine's envoy at the United Nations, said he has reached out to the UN Security Council to discuss the move, which he said grossly violates a 2015 peace accord.