European governments say Moscow is stepping up a campaign of sabotage and interference against Ukraine's backers as the Kremlin's troops struggle on the front line there, more than four years after their February 2022 invasion.

After high-profile incidents such as an armed drone found at a German airport, European Commission chief Ursula von der Leyen earlier this month pitched establishing a new "emergency security protocol" to deal with the rising threat.

Von der Leyen said the mechanism -- similar to NATO's Article Four -- would allow any European Union country to convene urgent talks in case of crisis to help find consensus on responding to incidents in the grey zone below open aggression. 

"Today was a very initial discussion, which means that we take this forward," EU foreign affairs chief Kaja Kallas said. 

She said there was a clear desire among EU countries to avoid any overlap or competition with NATO and that the new European protocol should be more focused on action than talking. 

"Article Four in NATO is just consultations. It's not any kind of action plan," she said.

"So the emergency protocol is rather which tools can be used at the moment of aggression that is not armed aggression, that is under the threshold of Article Five. What member states could do."

EU ministers broadly welcomed the push to step up the bloc's response as they grapple for ways to combat what they see as the menace from Moscow.

"We need to be able to not just respond when incidents happen, but also pre-empt possible escalations -- work with member states, work with each other, to make sure that we have a strong response in place should something happen," said Irish foreign minister Helen McEntee, whose country is one of only four in the EU not in NATO.

"There's still a bit of work to do to work through what that might look like -- but certainly, there's a willingness from member states."

A senior EU official said that Brussels can already put "quite a lot on the table" to help countries respond to hybrid incidents if needed. 

That includes dispatching expert teams to help advise on how to bolster security, and increasing funding.

"Each country has to do their own measures to counter hybrid measures, but the European Union and NATO also have to do much more bigger measures, stronger coordination to counter these hybrid actions," said Finnish defence minister Antti Hakkanen. 

EU officials have said that they intend to come up with more fleshed out proposals in a new security strategy document they hope to release next month. 

Meanwhile, the EU imposed on Monday new sanctions on Russian institutions and officials responsible for the deportation of Ukrainian children and for barring an opposition party from running in a recent vote.

European Union member states slapped restrictive measures on 27 individuals and entities they said played a role in the forcible transfer of Ukrainian children to Russia as well as their "forced assimilation" and "militarised education".

Since Russia invaded Ukraine in February 2022, Moscow has been accused of forcibly transferring around 20,000 children from parts of Ukraine seized by its army.

The sanctions targeted, among others, the Moscow City Tourism Committee and two Russian companies operating in children's recreation. 

The European Council representing EU nations said they "engaged in organising activities focused on Russian history, war commemorations and military-patriotic education".

The measures also hit sports centres in Russia and a state-run children's camp in North Korea, where Brussels said Ukrainian children were taken to promote pro-Russian narratives.

The International Criminal Court in The Hague issued an arrest warrant for Russian President Vladimir Putin in 2023 over the abduction of Ukrainian children.

The EU's 27 countries also sanctioned prosecutors and judges, including three of Russia's supreme court justices, involved in barring the anti-war Yabloko party from tightly controlled parliamentary elections this month. 

The measures include asset freezes and travel bans.