Poroshenko posted his congratulation message on Facebook, Censor.NET reports.
"Congratulations of the third anniversary of liberation of Mariupol," the president wrote.
On June 13, 2014, a battle of the government forces (Azov Special Volunteer Battalion, Dnipro Battalion, and the National Guard, supported by the Armed Forces) against the "DPR" militants. As a result Mariupol was completely liberated from the separatists. The city had been occupied by pro-Russian forces for several months.