Ukrainian President Petro Poroshenko has promised not to use aircraft and heavy artillery in the army operation in Donetsk, Donetsk Mayor Oleksandr Lukianchenko said.

"The president promised they would not use the methods they had applied in Sloviansk, Kramatorsk and Luhansk in the case of Donetsk," Lukianchenko said at a press conference on Tuesday.

The relocation of supporters of the self-proclaimed Donetsk People's Republic to Donetsk was discussed at a meeting with the president attended by Party of Regions deputy Borys Kolesnikov, the mayor said.

Heavy armaments may cut off power supply to major industrial enterprises, and this is fraught with an ecological catastrophe, Lukianchenko said.