The number of Russian hybrid attacks against NATO countries has risen significantly, according to a senior alliance official.
More than 200 such incidents were recorded last year alone, the official said in Brussels, adding that routine "day-to-day" cyberattacks were not included in the figure.
NATO headquarters itself faces thousands of cyberattacks every month, the official said.
Referring to an explosive-laden drone found at Leipzig/Halle Airport in Germany, the official said the type of explosive discovered suggested that a Russian intelligence service had been directly involved.
"Semtex is not something you would hand out to a kid you recruited playing video games", the official said.
NATO, like the German government, considers the incident a hybrid attack even though the explosive device did not detonate.
According to the alliance, Russia is seeking to undermine political and practical support for Ukraine and prepare for a possible further escalation.
This includes reconnaissance of critical infrastructure and logistics chains as well as pre-positioning malware in important industrial control systems.
NATO is particularly concerned about the changing nature of the attacks, the official said, explaining that "numbers are up, severity is up, risk appetite is up."
NATO is seeking to strengthen deterrence through military measures and better protection of critical infrastructure.
The alliance also plans to establish a Critical Energy Infrastructure Network to exchange security information with operators and support joint emergency exercises, drone defence and cyber defence.
In particularly serious cases, NATO's supreme military commander could ask member states to deploy offensive cyber capabilities, the official said.