Alexis Tsipras
Greek Prime Minister Alexis Tsipras addresses members of his leftist Syriza party in parliamentReuters

Greek prime minister Alexis Tsipras has blasted European economic sanction on Russia over the Ukraine crisis.

The left-wing firebrand accused Brussels of hypocrisy over the sanctions, saying it was unfair not to pursue Russian oligarchs with money invested overseas.

"If you want to punish Russia, you need to punish all the countries where Russian mulit-billionaires have invested their assets," Tsipras told German magazine Stern.

The European Union has imposed increasingly harsh economic sanctions on Moscow since it annexed the Black Sea peninsula of Crimea from Ukraine in March 2014.

Initially targeting individuals with close ties to the Kremlin, the sanctions eventually expanded to cover entire sectors of Russia's economy and effectively cut off Russian banks' access to global financial markets.

For its part, Russia imposed retaliatory sanctions, banning imports of fresh fruit and vegetables from the European Union, a fact that Tsipras bemoaned.

"I want the EU to speak with one voice. But Greece is also suffering from the sanctions. Russian tourists are staying away, our agricultural sector is suffering," he said.

The European bloc recently imposed fresh sanctions on a well-known Russian singer who has voiced support for Russia's annexation of Crimea, as well as two deputy defence ministers.

Iosif, or Joseph, Kobzon, is widely thought of as the Russian Sinatra in his home country but has also a long-standing member of parliament.

Imposed just one day after the EU and Russia negotiated a ceasefire deal between Kiev and pro-Russian separatists in eastern Ukraine, Moscow said the latest sanctions went against common sense.

The EU has accused Russia of fuelling the conflict in eastern Ukraine, by supplying pro-Russian rebels with manpower and firepower as they seek to establish autonomous republics in Ukrainian territory close to the Russian border.

More than 5,400 people have been killed since the fighting erupted in April last year.

Russia has denied its soldiers are operating in eastern Ukraine.