Poroshenko announced the exchange on his official website, which showed a photograph of him meeting early on December 1 with the freed Ukrainian, Andriy Hrechanov. Poroshenko said he pardoned Vladimir Starkov, who was arrested in July in eastern Ukraine and later sentenced to 14 years in prison. Ukrainian security services had released a video in which Starkov acknowledged being a Russian military officer, Radio Liberty reported. Russia has been denying sending troops and weapons to eastern Ukraine, where separatists have been fighting government troops since April 2014 in a conflict that has killed more than 7,900 people. A ceasefire has largely held since September.