European foreign ministers slapped sanctions on Russian mercenary outfit Wagner on Monday and touted what they warned would be an unprecedented economic response to any military assault on Ukraine.

Following a meeting of G7 ministers in Liverpool at the weekend, where the US and major allies warned the Kremlin of "massive" consequences if it invades, the 27 EU ministers met Monday in Brussels.

They first approved a list of eight names and three companies associated with Russia's private military company Wagner to be added immediately to existing sanctions regimes.

Next, they signalled their readiness to impose huge new measures targeting Russia's economy if a troop build-up near the Ukrainian border leads to direct military action.

"Allow me to say, once again, firmly that the European Union is standing united in support of Ukraine's sovereignty and territorial integrity," EU foreign policy chief Josep Borrell told reporters after the talks.

"The ministers -- all of them -- have been very clear today that any aggression against Ukraine will come with political consequences and with a high economic cost for Russia.

"We are globally coordinating with our transatlantic and like minded partners," he added,

Before the talks, Lithuania's Gabrielius Landsbergis stressed that the sanctions threat was a deterrent but that, if they proved necessary, they would have to be on an "unprecedented scale".

The meeting on Monday was the first EU foreign affairs council for Germany's new foreign minister, Annalena Baerbock, a Green politician who came to office last week in Chancellor Olaf Scholz's new coalition.

Berlin holds one of the most important cards in the sanctions deck, if it decides that President Vladimir Putin's actions warrant blocking the Nord Stream 2 gas pipeline from Russia to Germany.

Asked about the threat to Ukraine before heading to Brussels, Baerbock told ZDF television that "in the event of further escalation, this gas pipeline could not come into service."

After the Brussels meeting, Baerbock insisted that Germany's position on the pipeline had been made clear, without repeating it, and said "any action by Russia would have severe diplomatic consequences."

Separately, in a sign of Brussels' determination to address what it sees as the Kremlin's efforts to "destabilise" Ukraine, Syria, Libya and several African countries, sanctions were slapped on Wagner.

EU foreign policy chief Josep Borrell said any aggression against Ukraine would be met with "political consequences and with a high economic cost for Russia"
EU foreign policy chief Josep Borrell said any aggression against Ukraine would be met with "political consequences and with a high economic cost for Russia" AFP / JOHN THYS

Wagner is said to be financed by 60-year-old Saint Petersburg businessman Yevgeny Prigozhin, who has already been hit with EU and US sanctions for destabilising Libya and meddling in US elections.

In addition to the Wagner firm and three linked companies, the sanctions list targeted eight individuals, including the group's alleged commander.

Those sanctioned included:

Dmitry Utkin, a 51-year-old former lieutenant colonel in Russian military intelligence, once decorated by Putin and now said to be Wagner's commander and responsible for mercenary operations in Ukraine.

Utkin is accused of extrajudicial killings, including allegedly ordering a Syrian deserter to be tortured to death and filmed.

Alexander Kuzentsov, a 44-year-old Russian said to lead Wagner's 1st Attack and Reconnaissance Company under the call sign "Ratibor", accused of threatening the peace and security of Libya.

Retired colonel Andrei Roshev, 68, a founding executive director of Wagner now commanding mercenary troops in Syria in support of Bashar al-Assad's regime under the call sign "Siedoy".

The talks on Monday will also help prepare for the EU leaders' meeting with the "Eastern Partnership" -- Ukraine, Georgia, Moldova, Armenia and Azerbaijan -- on Wednesday.

Belarus left the group after the EU accused strongman Alexander Lukashenko of rigging his re-election, but opposition leader Svetlana Tikhanovskaya is in Brussels.

The EU wants to present its eastern neighbours with a united front against what it sees as Russia's destabilising meddling in the region, a senior European diplomat told AFP.

But on the question of China -- accused of persecuting the Uyghur minority, threatening Taiwan and cracking down on freedoms in Hong Kong -- there is less agreement between EU capitals.

The United States and some of Washington's allies have announced that they will not send diplomats or top officials to the Winter Olympics in Beijing, in protest against China's actions.

But Europe is divided -- with France dismissing talk of a diplomatic boycott as a small and useless measure -- and in the end the ministers did not find time to address the issue.