LONDON 

Turkey has "legitimate security concerns" regarding its southern border, NATO secretary general reiterated on Monday.

Jens Stoltenberg said "no other ally suffered more terrorist attacks," and "no other ally is more exposed to instability, turmoil and violence from the Middle East".

Speaking at the 65th NATO Parliamentary Assembly in London, Stoltenberg underlined that no other ally hosts more Syrian refugees than Turkey.

Urging Turkey to act with "restraint and in coordination" with other allies, the NATO chief said he has shared his concerns about Turkey’s latest operation with Turkish President Recep Tayyip Erdogan and Foreign Minister Mevlut Cavusoglu.

Stoltenberg said the international community must find a sustainable solution to the issue of foreign fighters held in camps in Syria.

The NATO chief said he shared his "concerns" about the Operation Peace Spring with Turkish officials during his Istanbul visit last Friday.

"The only way to understand what’s going on there is also to understand the important role Turkey played," he said.

"Turkey is important for the NATO," said Stoltenberg and added: "It has proven important in many ways not least in the fight against Daesh".

He also reminded the parliamentarians from NATO countries that the US-led coalition benefitted from the infrastructure and bases in Turkey during the fight against the Daesh, and stressed that the terrorist organization has not completely disappeared.

The allies should keep their unity in fight against Daesh, he added.

"We need a more coordinated approach from the international society in general and the NATO allies in particular to deal with the issue of foreign fighters," Stoltenberg said, also urging for a more coordinated effort to tackle the issue.