Moscow will not allow the mass killing of pro-Russian rebels in eastern Ukraine, Russian President Vladimir Putin warned, arguing that both sides need to make concessions for a floundering peace deal to succeed.

Putin's statement in an interview with German ARD television came as European Union foreign ministers met in Brussels to discuss a response to the continuing fighting in Ukraine and German Chancellor Angela Merkel declared that the conflict was not just about Ukraine but about peace across Europe.

In the interview broadcast late Sunday, Putin said he still believes in the success of peace efforts in eastern Ukraine, where pro-Russian rebels have been battling Kiev's troops in a conflict that has claimed more than 4,000 lives.

The Russian leader blamed the fighting on the failure by both the rebels and Ukrainian troops to pull back from the front line — a key requirement under a September cease-fire.

In the rebel-held stronghold of Donetsk, officials said Monday that one civilian had been killed and eight injured in fighting over the weekend. The pound of artillery fire could be heard in the city throughout the morning.

After Ukraine announced Friday that it would suspend banking services in rebel-held areas, Donetsk residents huddled outside banks Monday, waiting to withdraw their dwindling cash.

On the Ukrainian side, six troops were killed and nine wounded in clashes Sunday, according to the Ukrainian National Security Council. Unidentified attackers also killed three traffic police, it said.

The Kremlin has repeatedly denied claims by Ukraine and the West that Moscow has been fueling the rebellion with troops and weapons. Putin dodged the question in the ARD interview, saying "in today's world, anyone waging a fight that they believe fair will always find weapons."

He accused the West of turning a blind eye to Ukraine's use of heavy weapons against residential areas in rebel-held areas.

"You want the Ukrainian central authorities to annihilate everyone there, all of their political foes and opponents?" he said. "Is that what you want? We certainly don't. And we won't let it happen."

At a meeting Monday in Brussels, European Union foreign ministers mulled the possibility of further sanctions against Moscow for its actions regarding Ukraine. Federica Mogherini, the EU's foreign affairs chief, said more sanctions against Russia would not be effective and the EU should focus instead on encouraging meaningful reforms in Kyiv.

But Merkel, speaking in Sydney after the G20 summit in Australia, struck a more defiant note, saying sanctions would remain in place "as far and long as they are needed."

Merkel said Russia's annexation of Crimea "calls into question the horror of two World Wars and, after the end of the Cold War, Europe's framework of peace."

"Who would have thought that, 25 years after the fall of the Berlin Wall, after the end of the Cold War and the end of the world's separation into two blocks, something like this could have happened in the middle of Europe?" Merkel said. "Old ways of thinking in spheres of influence, which spurn international law, must not become accepted."

The German leader warned that regional conflicts like the one raging in eastern Ukraine "can very quickly broaden to major fires."

"It's not only about Ukraine. It's about Moldova, it's about Georgia, if it continues like this ... one has to wonder about Serbia, one has to wonder about the countries in the western Balkans," Merkel said.

World leaders at the G20 summit roundly criticized Putin over Russia's escalating aggression in Ukraine, but came up with no clear plan for increasing the diplomatic pressure on him.