A surprise proposal from Germany and Turkey, for NATO to help tackle the migrant crisis, has been on the agenda of an alliance meeting in Brussels.
Carrying out sea missions against human traffickers is a suggestion.
Addressing the start of the two-day meeting of defence ministers, the NATO chief acknowledged the migrant issue.
“We face the most challenging threats to our security in a generation,” said Jens Stoltenberg.
“Continued unrest in Ukraine, failed and failing states in the south, the spread of terrorism, and the largest refugee and migrant crisis in Europe since the end of World War II.”
Many migrants arriving in Europe are helped by smugglers. Germany says it would take part in a NATO mission against human traffickers in the Aegean.
“It is good That turkey has asked NATO to step up maritime surveillance in the Aegean sea region,” said Ursula von der Leyen, German Defence Minister.
“The aim must be to complicate, if not make impossible, the treacherous business of smugglers involved in illegal migration.”
The push for NATO involvement, which comes after German Chancellor Angela Merkel visited Turkey, is already raising eyebrows.
Speaking from outside NATO’s headquarters, euronews reporter Andrei Beketov said: “An American source said it’s not really NATO’s job to police refugee streams. A British official told us the alliance will be fully preoccupied in the coming months with threats from the East and South.”
He continued: “The counter-ISIL coalition will meet in these headquarters on Thursday, but NATO insists it has nothing to do with its plans and only provides a venue. NATO seems to be reluctant to go beyond its remit.”