The NATO allies will meet on Tuesday to discuss Belarus' forced diversion of a European passenger flight carrying an opposition activist.
"Allies are consulting on the forcible landing of the Ryanair plane by Belarus and ambassadors will discuss it tomorrow," a NATO official told AFP Monday.
Several NATO members have denounced Belarus' decision to force the Ryanair flight from Athens to Vilnius to land and to detain dissident journalist Roman Protasevich.
EU leaders, most of whose governments are also NATO allies, were to meet later Monday to discuss imposing tougher sanctions on Alexander Lukashenko's regime.
On Sunday, NATO secretary general Jens Stoltenberg denounced the diversion as a "serious and dangerous incident."
Some member states have gone so far as to call the action a "state hijacking" and Belarus' neighbour Poland called in an "act of state terrorism."
But Belarus' main ally Russia has dismissed Western concerns, and argued that it is for international aviation authorities to evaluate the incident.