Jean-Claude Juncker has called for an end to “Russia-bashing” two months after scores of Moscow’s diplomats across the EU were expelled in response to the use of a nerve agent in the UK.

The president of the European commission said he believed it was time to renew ties with Vladimir Putin’s country, given its size and importance.

“I do think we have to reconnect with Russia,” Juncker told an audience in Brussels. “I am not very happy with the state of our relations. We will never accept what Russia did with Crimea or eastern Ukraine. But nevertheless, we have to have in mind that the entire territory of the European Union is about 5.5m sq km. Russia [is] 70.5m” sq km. [Editor’s note: Russia’s size is actually 17.1m sq km.]

“So we have to come back to, I wouldn’t say normal relations with Russia, but there are so many areas, so many domains, where we can cooperate in a better way with research and innovation and others. Not forgetting what our differences and divergences are. But this Russia-bashing has to be brought to an end.”

The comments, made during a thinktank event on EU reform, will raise eyebrows in the UK. Theresa May, the prime minister, campaigned for a strong response to the attempted murder of the former Russian spy Sergei Skripal and his daughter, Yulia, in Salisbury in March.

Last week the Dutch prime minister, Mark Rutte, said he was determined to hold the Kremlin to account after the Netherlands and Australia formally accused Russia of playing a role in the downing of Malaysia Airlines flight MH17 over eastern Ukraine in 2014.

Juncker’s intervention will also dismay some in Washington. The US administration has been lobbying the EU to apply tougher sanctions on Russia over Kremlin attempts to meddle in western democracies.

Countermeasures applied by the EU against Russia after the 2014 illegal annexation of Crimea were resisted by some member states, and have failed to keep up with those of the US. In Italy, the Five Star Movement and the League, the leading populist parties, want to lift the EU’s sanctions on Russia.

• This article was amended on 4 June 2018 to note that contrary to Jean-Claude Juncker’s figure of 70.5m sq km, Russia’s size is 17.1m sq km.