Kiev: Ukraine said on Tuesday that the leaders of Germany and France had agreed to back "firm" steps against Russia should pro-Moscow rebels hold disputed elections in the ex-Soviet state's separatist east.
A top aide to President Petro Poroshenko said German Chancellor Angela Merkel and French President Francois Hollande had agreed at trilateral talks in Berlin on Monday to a set of "red lines" Russia must not cross.
"European leaders agreed on a set 'red lines' whose violation by Russia would prompt a firm EU response," deputy administration chief Kostyantyn Yeliseyev told reporters.
"One of these lines is the fake elections that the (rebels) of Donetsk and Lugansk intend to hold on October 18 and November 1," he said in reference to the two separatist regions.
"Russia must pressure its loyalists to cancel these so-called elections. They will not be recognised and only pose a serious threat to the Minsk (peace) process if they go ahead," he told reporters.
Unceasing fighting has left in shambles a truce deal that the Merkel and Hollande helped negotiate in the Belarussian capital Minsk in February.
A spokesman for the army in Kiev said four servicemen had been killed and 12 injured in mortar fire exchanges across the Donetsk area.
"The situation is getting worse," Oleksandr Motuzyanyk told a daily press briefing. "The rebels' attacks have intensified."
Pro-Russian militia commander Eduard Basurin told AFP that Ukrainian shells had killed one civilian and wounded another 12 in the rebels' de facto capital of Donetsk and their nearby stronghold of Gorlivka.
The continuing violence brings to nearly 6,900 the number of people killed since Ukraine's industrial east was overrun by pro-Kremlin gunmen and what Kiev believes are Russian troops in March 2014.
But the two EU heads of state still see the Minsk deal as the only solution to a conflict that has shattered Moscow's relations with the West and renewed fears of Russia's invasion of former communist eastern European states.