Russian President Vladimir Putin has signed a decree to expedite applications for Russian citizenship by Ukrainians living in separatist-held areas.

The decree published on the Kremlin's website Wednesday says that people living in the parts of Ukraine's Donetsk and Luhansk regions under separatist control will have their applications considered in under three months.

The move is likely to further exacerbate relations between Ukraine and Russia, which annexed Ukraine's Crimean peninsula and threw its weight behind separatist rebels in the east.

The decree comes just days after TV comedian Volodymyr Zelenskiy was elected as the new Ukrainian president; he 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.