Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Turkish jets launched a fresh wave of airstrikes in Northern Iraq after NATO backed the country in its war against militant uprisings. Images of bombs hitting several positions of the outlawed Kurdistan Worker’s party (PKK) were released by the country's armed forces. The air raid came after all members of the 28-nation military alliance gave Turkey its full backing. Secretary General Jens Stoltenberg said NATO supported Ankara in the face of 'terrible acts of terror' and instability along its southern border. 'The security of the alliance is indivisible,' ambassadors from all 28 nations later declared in a statement after the meeting, called to assess the threat posed by ISIS and Kurdish rebels.All members of 28-nation military alliance gave their full support to AnkaraComes after Ankara ended ceasefire with raids against PKK bases in IraqTurkey blamed explosion that crippled major gas line on Kurdish rebelsAnkara has rounded up some 900 suspected ISIS members and militants 
 Question:However, while public statements stressed _ unity, an official said members also used the closed-door meeting to call on Turkey not to use undue force and to continue peace efforts with representatives of the Kurdish minority.

NATO