NATO chief: Russian incursions into Turkish airspace no accident

NATO Secretary General Jens Stoltenberg listens to questions from journalists during a media conference at NATO headquarters in Brussels on Tuesday, Oct. 6, 2015. NATO defense ministers will meet on Thursday, Oct. 8, 2015 to discuss, among other issues, the situation after a Russian fighter jet entered Turkish airspace from Syria over the weekend. (AP Photo/Virginia Mayo) (The Associated Press)

NATO Secretary General Jens Stoltenberg speaks during a media conference at NATO headquarters in Brussels on Tuesday, Oct. 6, 2015. NATO defense ministers will meet on Thursday, Oct. 8, 2015 to discuss, among other issues, the situation after a Russian fighter jet entered Turkish airspace from Syria over the weekend. (AP Photo/Virginia Mayo) (The Associated Press)

NATO's secretary-general has rejected Moscow's claim that its military incursion into alliance airspace over Turkey wasn't intentional or important, saying there were two separate incidents and "the violation lasted for a long time."

Jens Stoltenberg, the NATO chief, told a news conference in Brussels on Tuesday the reported incidents were "very serious."

Stoltenberg added, "It doesn't look like an accident, and we've seen two of them over the weekend."

On Monday, NATO ambassadors met in special session and condemned what they termed Russia's "irresponsible behavior."

The ambassadors also called on Russia to cease such practices.