Ukrainian President Petro Poroshenko has stated the deteriorating situation in Donbas in a telephone conversation with German Federal Chancellor Angela Merkel, French President Francois Hollande and Russian President Vladimir Putin, the presidential press service has said in a report.

"The Ukrainian president stated the deteriorating situation in Donbas, including a rise in attacks by the militants," the report said.

Poroshenko emphasized the need to release all hostages and persons illegally held in Russia, including Ukrainian pilot and MP Nadia Savchenko.

The sides welcomed the decision of the Trilateral Contact Group to repair the damaged water supply facilities and railroad tracks.

The issue of gas supply to Ukraine was highlighted, and "the interlocutors agreed to boost the signing of an agreement in the Ukraine-EU-Russia format regarding Russian gas supply to Ukraine," the press service said.