Commander of Ukraine's Joint Forces Operation (JFO) Serhiy Nayev says the Ukrainian army has advanced 15 square kilometers in Donbas, eastern Ukraine, since the beginning of the operation at the end of April 2018.

Read also"They will drown in their own blood": Ukraine comments on threat of Russia's new offensive

"In the course of stabilization actions since the beginning of the JFO, we have managed to ensure and maintain full control along the contact line with the enemy, the proper level of security and stability in all sectors of the operation. Establishing security bands in the Volnovakha, Horlivka, Sievierodonetsk and Svitlodarsk directions allowed us to retake about 15 square kilometers of Ukrainian territory, including populated localities," he said.

At the same time, Nayev stressed the Ukrainian military adhere to the Minsk agreements and observe the ceasefire, but "adequately respond to the provocations of the Russian Federation."

An Anti-Terrorist Operation (ATO) was completed in Donbas on April 30, switching the format to that of the Joint Forces Operation of the Armed Forces of Ukraine.