EU defense ministers on Monday discussed creating a NATO-style emergency protocol that would let member states convene urgent talks to coordinate responses to what European governments call Russian hybrid attacks.
The proposed Emergency Security Protocol, pitched by European Commission President Ursula von der Leyen, would resemble NATO's Article 4 consultations.
European ministers broadly welcomed the push, though some diplomats warned it could overlap with NATO's own processes.
European governments blame Moscow for a rising campaign of sabotage, arson, cyberattacks and drone incursions against Ukraine's backers, including an attempted armed drone attack on Germany's Leipzig/Halle airport.
Such incidents have sparked outrage but no clear collective response.
Von der Leyen said the mechanism would allow any EU country to call urgent talks in a crisis to build consensus on responding to incidents below the level of open aggression.
"As the threat level climbs, so must Europe's preparedness," she said earlier this month, proposing a "counter-hybrid playbook" and "a mechanism to flank NATO's 'Article 4.'"
EU foreign policy chief Kaja Kallas said the discussion would look at "the broader strategy against hybrid attacks."
"What are the tools that we can use on different levels?" she said.
A senior EU official told Financial Times (FT) that Brussels can already put "quite a lot on the table," including expert teams to advise on security and increased funding.
EU officials plan to set out fuller proposals in a new security strategy expected next month.
"If we are facing hybrid warfare, we need to have hybrid defense," EU Defense Commissioner Andrius Kubilius told the FT.
"Very simply, if we are facing painful hybrid threats or actions, our answer should be painful in a similar way," he said, adding, "Russia needs to know that there will be answers, and they can be painful."
"We need to be able to not just respond when incidents happen, but also pre-empt possible escalations," said Irish Foreign Minister Helen McEntee, whose country is one of four EU members 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," she added.
"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 Defense Minister Antti Hakkanen.
Several European diplomats told the FT there was widespread confusion over what the protocol would do and wariness over a mechanism that could compete with NATO decision-making.
"I'm not sure that anyone thinks the way to fight back against the Russians is to hold more meetings," one diplomat said.
NATO Secretary-General Mark Rutte said the alliance already has response options.
"They are not always public, so we cannot always talk about it. They are not always symmetrical. It's not always tit-for-tat, but I can assure you the Russians know," he said.
Article 4 has been invoked nine times in NATO's history, including twice last year. Denmark's intelligence service warned this week that Russia could launch a limited military attack against a NATO country in the coming months.