‘We have to act quickly’ on Russia, European Union leaders told

Despite tough rhetoric decrying Russia’s increasing military involvement in Ukraine, European Union leaders on Sunday stopped short of imposing new sanctions against Moscow right away.

Instead, the 28-nation bloc’s heads of state and government tasked their executive body to “urgently undertake preparatory work” for tougher economic sanctions, according to summit chairman Herman Van Rompuy.

The sanctions will depend on the evolution of the situation but “everybody is fully aware that we have to act quickly,” he said. The preparatory work will start Monday.

The fighting between the military and Russia-backed separatists in eastern Ukraine has claimed 2,600 lives, according to U.N. figures. NATO said last week that at least 1,000 Russian soldiers are in Ukraine, which Russia denies. And 20,000 Russian troops are amassed just across Ukraine’s eastern border, NATO says.

The U.S. and the EU have imposed sanctions against dozens of Russian officials, several companies as well as the country’s financial sector and arms industry. Moscow has retaliated by banning food imports.

German Chancellor Angela Merkel said the new sanctions would target the same sectors as previous punitive measures, which also included an export ban for some high technology and oil exploration equipment.

Several European leaders had called for additional sanctions at the outset of the meeting in Brussels, but the fear of an economic backlash apparently prevailed and led the bloc to grant Russia another chance to avoid tougher action. New sanctions would have required unanimity among the leaders.

Russia is the EU’s No. 3 trading partner and one of its biggest oil and gas suppliers. The EU, in turn, is Russia’s biggest commercial partner, making any sanctions more biting than similar measures by the U.S.

Ukrainian President Petro Poroshenko, who briefed the leaders at the beginning of their talks, said a strong response was needed to the “military aggression and terror” facing his country.

“Thousands of the foreign troops and hundreds of the foreign tanks are now on the territory of Ukraine,” Poroshenko told reporters. “There is a very high risk not only for peace and stability for Ukraine, but for the whole … of Europe.”

European Union threatens to enact new sanctions against Russia over the incursion of troops on Ukrainian soil

NATO estimates at least 1,000 Russian soldiers are in Ukraine, though Russia denies any military involvement