Turkey will not support President Barack Obama’s call for a military response to ISIS, according to an official source quoted by Agence France-Presse on Thursday. It will not allow the U.S. to use air bases in Turkey for missions against the Islamist terror group, and will focus instead on humanitarian missions. 

The message comes as Obama pledged to build an international coalition against ISIS in a national address on Wednesday.

In refusing to join the fight, Turkey has apparently reversed its commitment to a common strategy agreed upon at the recent NATO summit–and has also dealt a blow to Obama’s diplomatic efforts, which are central to his new strategy on ISIS. 

The rejection of assistance after Obama’s speech is particularly striking, given that Turkish President Recep Tayyip Erdogan is often described as Obama’s closest friend among foreign leaders.