NATO Secretary General Mark Rutte warned that Russia must face "devastating" consequences if it attacks Ukraine again after any future peace deal, as he outlined a three-layer security guarantee system during a press conference in Poland on Wednesday (December 18).

"Putin has to know that after a peace deal, if he tries to attack Ukraine again, the reaction will be devastating," Rutte said alongside Polish Defence Minister Wladyslaw Kosiniak-Kamysz.

Rutte said that several NATO allies, including Hungary, the United States, and Slovakia, currently oppose Ukraine's NATO membership, making alternative security arrangements necessary.

The proposed security framework includes Ukrainian armed forces as the first line of defence, a European-led multinational force coordinated by the coalition of the willing as the second layer, and U.S. participation as the third element.

European leaders agreed on Monday (December 15) that any decisions on potential Ukrainian territorial concessions to Russia could only be made once robust security guarantees were in place.

The statement from ten European leaders and EU Commission chief Ursula von der Leyen came after they met in Berlin to support peace talks between U.S. and Ukrainian negotiators.

The proposed security guarantees would allow Ukraine to maintain armed forces of around 800,000 troops and include a U.S.-led ceasefire monitoring mechanism. U.S. officials described the proposed protections as "Article 5-like," referencing NATO's mutual defence pledge, though Ukraine would not be a NATO member.

DESCRIPCIÓN DE IMÁGENES

Russia to face 'devastating consequences' if it attacks Ukraine again, NATO says

VIDEO SHOWS: PRESS CONFERENCE BY NATO SECRETARY GENERAL MARK RUTTE, POLISH MINISTER OF DEFENCE WLADYSLAW KOSINIAK-KAMYSZ

RESENDING WITH COMPLETE SCRIPT TO FOLLOW

SHOWS: BEMOWO PISKIE, POLAND (DECEMBER 18, 2025) (REUTERS-Access all)

1. NATO SECRETARY GENERAL MARK RUTTE, POLISH MINISTER OF DEFENCE WLADYSLAW KOSINIAK-KAMYSZ ARRIVING AT PRESS CONFERENCE

2. PRESS CONFERENCE IN PROGRESS

3. (SOUNDBITE) (English) NATO SECRETARY GENERAL, MARK RUTTE, SAYING:

"Putin has to know that after a peace deal, if he will try to attack Ukraine again, the reaction will be devastating. And this is exactly how we are designing these security guarantees."

4. CAMERA OPERATORS FILMING / PRESS CONFERENCE IN PROGRESS

5. (SOUNDBITE) (English) NATO SECRETARY GENERAL, MARK RUTTE, SAYING:

"As we speak, a couple of allies are saying they will not give their consent and therefore will withhold unanimity to Ukraine entering NATO. Countries like Hungary, the United States, Slovakia, and maybe a couple of others. So that's the practical point of it. So that leaves us then with the question: if a peace deal is done on Ukraine, a long-term ceasefire or a full peace deal, how do we prevent the Russians from ever attacking Ukraine again? How do we prevent a repeat of what happened after Minsk II in 2014-2015? And this is where the security guarantees come into place."

6. PRESS CONFERENCE IN PROGRESS

7. (SOUNDBITE) (English) NATO SECRETARY GENERAL, MARK RUTTE, SAYING:

"And the security guarantees, as they are currently being designed, have three layers. Layer one is the Ukrainian Armed Forces. They will be, of course, like in Poland and everywhere in NATO territory, in this case, outside NATO territory, in Ukraine will be the first line of defence. The second line of defence is, of course, what the coalition of the winning, under the leadership of the United Kingdom and France, has been designing over the last couple of months: how can the Europeans help here, together with Canada, to make sure that the peace will be sustained? And the U.S., and this is the third element of this, the American President said in August that he wants the U.S. to be part of those security guarantees. And at the moment, discussions are ongoing about what that exactly would mean and how, then, this collective package of security guarantees would look like. That's currently the debate going on. It's extremely important because, indeed, after the peace deal, if not NATO, and NATO for practical reasons is not possible now. How do we prevent a further attack from Russia?"

8. VARIOUS OF PRESS CONFERENCE IN PROGRESS

9. RUTTE AND KOSINIAK-KAMYSZ SHAKING HANDS AND LEAVING