Finland has warned the US against using the term, arguing it risks diluting the bloc's core mutual defense clause

Finland has privately urged US officials to avoid describing future security commitments to Ukraine as "Article 5-like," warning the terminology could undermine NATO's foundational mutual defense clause, according to a leaked diplomatic cable.

Under NATO's Article 5, an attack on one member of the bloc is treated as an attack on all others, warranting a military response. 

A January 20 US State Department cable, obtained by Politico, has reportedly revealed that Finnish Foreign Minister Elina Valtonen cautioned visiting American lawmakers that such language risks conflating NATO's absolute Article 5 guarantees with whatever bilateral promises nations might make to Kiev. 

Valtonen also reportedly stressed the need for a clear "firewall" between the US-led military bloc and future security arrangements for Ukraine. Finland's defense minister allegedly made similar points in a later meeting, according to the cable.

Amid the ongoing US-led peace negotiations on the Ukraine conflict, several media reports have suggested that Washington has offered "Article 5-like" security guarantees for Kiev as part of a peace roadmap, listing Finland, which joined NATO in 2023, as one of the potential guarantors which would defend Ukraine in case of a future attack.

Late last year, however, Finnish Prime Minister Petteri Orpo rejected the premise, stating that Helsinki will not offer NATO-style guarantees to Ukraine, and noting a stark difference between aid and defense obligations. 

"We have to understand that a security guarantee is something very, very serious. We're not ready to give security guarantees, but we can help with security arrangements. The difference between them is huge," he said.

Moscow has said it does not oppose security guarantees for Ukraine in principle but has insisted they must not be one-sided or directed against Russia, and should follow a peace deal rather than precede one. 

Russian officials have also warned against any sort of NATO troop deployment to Ukraine, whether as peacekeepers or otherwise, warning this could lead to a direct confrontation with the bloc.