Jens Stoltenberg was speaking ahead of a NATO summit in Warsaw in July

Ilham Aliyev and Serzh Sargsyan met in Vienna for the first time since an outbreak heavy fighting at the start of April

The talks in Vienna were aimed at strengthening the ceasefire after dozens were killed in April

The Armenian president and the EU's foreign policy chief discussed the ongoing situation in Nagorno-Karabakh

Ilham Aliyev and Federica Mogherini discussed the fragile ceasefire in Nagorno-Karabakh

The meeting between the Presidents of Armenia and Azerbaijan can help strengthen the cease-fire and open the way for the resumption of negotiations

"To reduce the risk of further violence, they agreed to finalize in the shortest possible time an OSCE investigative mechanism."

The presidents of Armenia and Azerbaijan were meeting for the first time since fierce fighting last month, which killed dozens

According to sources, it should strengthen the determination to bring about a political settlement to the conflict.

The two leaders said the pipeline has helped secure peace and stability in the region