Secretary General Jens Stoltenberg said NATO members meeting in Turkey Thursday discussed ways to deepen defence cooperation with non-NATO members Finland and Sweden.
According to Reuters news agency, Stoltenberg told journalists that possible closer collaboration would focus on increased Russian activity in the Baltic Sea.
"We have agreed to look at ways to hold more consultations and to share more information about what is happening in the Baltic Sea region and beyond so that we all have the fullest possible picture," he said.
"We will also look at how we can conduct more exercises together with Finland and Sweden," he added.
Both Finland and Sweden have been rattled by a spate of airspace incursions by Russia. And late last year Swedish submarines launched what was locally dubbed "the hunt for Red October" in the Swedish archipelago following reports that a suspected submarine had been detected in the waters off Stockholm.
The Finnish navy meanwhile dropped low-impact depth charges in the sea off Helsinki in April when its surveillance network detected an as-yet unidentified object.
Opinion polls in Sweden last year showed a majority supporting NATO membership for the first time. In Finland, there has traditionally been little backing for the alliance, but recent polls suggest it's slowly gaining approval.
For its part, the Kremlin has expressed consternation over the growing relationship between Finland and Sweden and the military alliance.