The EU extended damaging economic sanctions against Russia on Monday amid sharp differences over relations with Moscow which struck back with a furious tirade and its own import ban against Ukraine.

Russia said the move, prolonging sanctions imposed over the Ukraine conflict, gave the lie to EU claims of wanting better relations with Moscow to counter common threats such as terrorism.

"It is necessary to point out that instead of building constructive cooperation to counter the key challenges of our times such as international terrorism, the EU in Brussels prefers to continue its short-sighted game of sanctions," the Russian foreign ministry said in a statement.

For its part, the European Council of all 28 EU member states said it rolled over the economic sanctions because the peace accords, agreed by France, Germany, Ukraine and Russia at talks in the Belarusian capital Minsk, would not be fully implemented by the end of this year as required.

"Since the Minsk agreements will not be fully implemented by December 31,, the duration of the sanctions has been prolonged whilst the Council continues its assessment of progress in implementation," it said.

EU officials say that while there has been an improvement on the ground in eastern Ukraine where pro-Moscow rebels hold sway, Kiev still does not have control of the border with Russia, a key element in the Minsk accord.

There can be no let up in sanctions until Russia uses its influence with the rebels to ensure the ceasefire holds for good, they say.

The announcements came as top EU, Ukrainian and Russian officials met in Brussels for talks on the introduction of a free trade pact between Kiev and Brussels from January 1, part of a wider association agreement.

Russia bitterly opposes the 2014 EU association agreement, which sparked the overthrow of Ukraine's pro-Moscow president Viktor Yanukovych, and says the free trade deal will allow a flood of cheap EU products into one of its key markets.

Russian Prime Minister Dmitry Medvedev said: "Neither Ukraine nor the European Union are ready to sign a legally binding agreement which would take into account Russia's interests."

The EU sanctions decision was originally meant to have been a formality, with member country ambassadors supposed to approve the rollover in early December -- and thereby avoid a debate at the leaders summit which took place last week in Brussels

But it ended up delayed after several countries, especially Italy, raised questions about how the EU could both punish Russia over Ukraine yet still seek its help on key international issues, including the Syrian conflict.

Italy has traditionally close ties with Russia and wanted EU leaders to at least discuss the issue, but Prime Minister Matteo Renzi could not get it on the formal agenda despite his best efforts.

"I found it surprising that we should want to confirm the sanctions without first having had a little discussion," he said after the summit.

German plans to build a second pipeline -- Nordstream 2 -- to carry Russian gas under the Baltic Sea added to Renzi's frustration.

Rome reportedly sees it as hypocritical that Berlin should pursue a major deal when the rest of the bloc is being asked to sacrifice their interests in order to lay down the law to Russia.

EU President Donald Tusk, who chaired the summit, said the talks on Nordstream were heated. "It was an emotional discussion."

Reflecting the discordant forces at work as the announcements were being made Monday, French Defence Minister Jean-Yves Le Drian flew into Moscow for talks on bolstering cooperation against Islamic State jihadists in Syria.

Putin has repeatedly dismissed the sanctions which target Russia's bank, oil and defence sectors as ineffective and counter-productive to the better understanding the EU says it wants.

The EU first imposed economic sanctions against Russia for a year after the July 2014 downing of a Malaysia Airlines jet, blamed on pro-Russian rebels in eastern Ukraine.

In June 2015, they were renewed for six months to January 2016 and will now run until end-July.

Besides the economic sanctions, the EU has imposed a separate travel ban and asset freezes on Russian and Ukrainian individuals blamed for the conflict in eastern Ukraine. These measures run to March.

It has also targeted those involved in Moscow's annexation of Crimea in March 2014 with similar measures which expire in June.