“If they [Ukraine] give an excuse to the EU there are at least five countries right now that want to say: ‘Whoa, we want out [of the sanctions]’,” he said.

He said “there’s an overwhelming instinct in Europe to say: ‘Hey, before you guys [Ukraine’s Petro Poroshenko] became president, this was owned by Russia anyway. They had a puppet there. What difference does it make?’.”

He also said “I’ve never seen Europe in as much self-doubt in my career … because of migration, because of Brexit”.

In an insight into US diplomacy, Biden said he had spent “two to three hours a week” on the phone with Ukraine’s leaders in recent years urging them to step up reforms.

He said he had told Poroshenko that unless he fired his former chief prosecutor, who was suspected of corruption, the US would hold back aid: “I said: ‘I’m not signing it. Until you fire him, we’re not signing’.”

Biden said he had targeted France, Germany, and Italy on keeping EU sanctions.

He said German chancellor Angela Merkel and French president Francois Hollande had previously been “stalwart”, but that Merkel is “now in a different position”.

He said Russia did not want to invade Ukraine, but "to totally destabilise the government, bring it down, and as a result get everything they had before and Europe going: ‘Well, that was too bad’.”

Biden’s reference to Merkel being in a “different position” comes amid the chancellor’s falling popularity in the refugee crisis.

The centre-left SPD party has also called for better Russia relations in its campaign for next year’s German elections.

That policy was on show on Wednesday when the SPD leader, German vice-chancellor Sigmar Gabriel, met Russian president Vladimir Putin in Moscow.

Phasing out?

“I’m doing what I can so that the sanctions, imposed after the annexation of Crimea, can be lifted step-by-step, and in the same measure as there is tangible progress in implementing the Minsk agreement," Gabriel said.

A Merkel spokesman, Juergen Hardt, retorted that her CDU party “cannot understand the remarks by minister Gabriel on the sanctions against Russia being phased out”.

"We strongly support the view of the G7 countries - that a lifting of the sanctions is coupled with the full implementation of the Minsk agreement”, Hardt said.

The G7 club of wealthy states includes Canada, France, Germany, Italy, Japan, the UK, and the US.

The Minsk accord is a ceasefire deal that obliges “foreign”, meaning Russian, forces to pull out of east Ukraine in return for Ukraine devolving power to the war-torn regions.

But Ukraine’s Poroshenko, in a speech at the UN assembly in New York on Wednesday, said he cannot hold local elections in the war zone, as per Minsk, unless Russia first leaves.

“We are constantly facing resistance by the Kremlin and its proxies who are doing their best to delay the peace process and shift responsibility for their own destructive action onto Ukraine”, he said.

EU sanctions

The EU has three packets of sanctions: economic measures against Russian banks and energy firms, a blacklist of Russians and Ukrainians, and a ban on doing business with Russia-annexed Crimea.

The economic sanctions expire in January unless they are renewed by consensus, with EU leaders to hold talks on the subject next month.

The other two sets of measures have already been rolled over until mid-2017.

But an investigation by the Reuters news agency, published on Wednesday, showed that two EU retailers, Germany’s Metro group and France’s Auchan, have supplied goods to supermarkets in Crimea.

Reuters said this was most likely done by selling stock to Russian subsidiaries, who then sold it to Crimea - a loophole in the EU regime.

The OCCRP, a club of investigative journalists from eastern Europe, two weeks ago also said EU states’ shipping lines flout the Crimea ban.

“Over the past two years, 24 vessels bearing EU countries’ flags, 43 vessels registered in the EU, and 22 vessels owned by EU beneficiaries have entered Crimea”, the OCCRP said, naming Germany, Greece, and Romania among the culprits.