Virginia Mayo, Associated Press
Lithuanian Foreign Minister Linas Linkevicius, right, speaks with the media as he arrives for a meeting of EU foreign ministers at the EU Council building in Brussels on Thursday, Jan. 29, 2015. EU foreign ministers hold an extraordinary meeting on Thursday to discuss the latest fighting in Ukraine and possible further sanctions against Russia.

BRUSSELS — France says European Union sanctions against separatists in eastern Ukraine and their Russian backers will be reinforced in an attempt to force all sides back to the negotiating table.

French European Affairs Minister Harlem Desir said ahead of Thursday's meeting of EU foreign ministers that the bloc needs "the maximum toughness" in the face of continued fighting against government forces.

The 28 ministers are expected to ask diplomats to come up with a series of sanctions proposals within the next two weeks, so they can be considered at an EU summit on Feb. 12.

If the fighting in Ukraine continues unabated, there would be few other choices for EU leaders to consider, said Britain's Europe minister David Lidington.

"It is the duty of the EU now to prepare options for the future including, I think it's now necessary, the possibility of further restrictive measures against Russia which our leaders could then consider depending on what happens on the ground," he said.

Desir said that "what will be decided today is to reinforce and broaden sanctions that target the separatists and those who back them, including those in Russia."

Pressure has built up since last weekend's attacks on Mariupol, when rockets crashed into a densely populated eastern district, killing 30 and wounding several dozen. International observers said a preliminary assessment indicated the attack had been mounted from rebel-held areas.

"It was a deliberate attack on civilians from the regions controlled by separatists, terrorists rather," said Lithuanian Foreign Minister Linus Linkevicius. He said there was increasing evidence of more Russian backing for the separatists.

"It is Russian war against Ukraine — to name names," he said.

Since Russia's annexation of Crimea, the EU has steadily increased restrictive measures. In July, the EU imposed economic sanctions which, combined with the drop in oil prices, have stung Moscow.

Meanwhile, Russia has extended its walkout from Europe's human rights watchdog after again losing its right to vote over the conflict in eastern Ukraine. The Parliamentary Assembly of the Council of Europe, meeting in the French city of Strasbourg on Wednesday, voted to renew sanctions against Russia at least until April. Russian delegate Alexei Pushkov said Thursday that his delegation's walkout would continue the rest of the year.