Ukrainian President Petro Poroshenko has proposed talks on a new ceasefire and is said to be waiting on a reply from pro-Russian rebels, a statement on his website reports.

Poroshenko had informed European Union foreign policy chief Catherine Ashton of a proposed time and place for the talks.

Ukraine's foreign minister and those of Germany, France and Russia agreed in Berlin on Wednesday that another meeting of the so-called contact group should be set up by this weekend with rebel leaders to agree on a more effective ceasefire.

The group includes a former Ukrainian president, Moscow's ambassador to Kiev and a high-ranking official from the Organisation for Security and Cooperation in Europe (OSCE).

Poroshenko announced a cease-fire on June 20, giving an opportunity for east Ukraine separatists to lay down their weapons.

On June 30, Ukrainian President announced the cease-fire over, amid 27 Ukrainian soldiers had been killed since the cease-fire began.

However, Poroshenko said he was willing to return to a cease-fire "at any moment" if it became clear that all sides were ready to carry out all aspects of the peace plan, including the freeing of hostages and creating effective border controls.