NATO Says Russian Warplanes in Turkish Airspace is 'Very Serious'

A NATO spokesperson has argued that two alleged mistakes in which Russian planes "accidentally" flew into Turkish air space are considered to be "very serious."

Jens Stoltenberg, NATO secretary general, said in a statement this week that the alleged claims by Russia that it accidentally flew into Turkish air space are "very serious," adding that NATO is still awaiting a "real explanation" from Moscow regarding the recent incidents.

"It doesn't look like an accident, and we've seen two of them over the weekend," Stoltenberg said at a news conference over the weekend.

"Russian combat aircraft have violated Turkish airspace," Stoltenberg continued, adding that "This is unacceptable."

The secretary general elaborated that the intelligence received by Turkish forces leads NATO to believe that the fly-ins were not an accident.

Turkey's Foreign Ministry issued a strongly-worded statement warning Russia of its violation.

"The Russian Federation will be responsible for any undesired incident that may occur," the ministry warned.

"The Russian aircraft exited Turkish airspace into Syria after it was intercepted by two F-16s from the Turkish air force, which were conducting patrols in the region," the ministry's statement added.

The comments from NATO come after the United States raised speculation regarding Russian-led airstrikes being carried out in Syria.

While Russia has claimed that the airstrikes are targeting Islamic State strongholds, the U.S. has argued that the air strikes may in fact be targeting opponents of Russian ally Bashar al-Assad, president of Syria.