The Financial Times reports.
"I'm a little concerned about this rather bellicose talk that Russia is going to test Article 5 (on NATO's collective defense) and that Europe is next in line. I think we should prepare for that, but I think it's unlikely," Stubb said.
According to him, recent public warnings about Russian aggression outside Ukraine distract leaders from helping Ukraine.
"I urge all European countries to become more Finnish. In other words, be more prepared. We need to prepare for the worst to avoid it," the Finnish president added.
Among the measures that other European countries should consider, Stubb mentioned conscription, which is mandatory in Finland.
He also called on NATO countries to "support Ukraine as long as necessary, and at this stage almost everything that is necessary" to repel Russia's spring offensive.
The Russian authorities are threatening NATO member states to curb the expansion of the Alliance's influence to other countries and to create information conditions to justify a possible long-term confrontation with the West.