NATO rejects Moscow's explanation that its warplanes violated the air space of alliance member Turkey by mistake. 

NATO Secretary-General Jens Stoltenberg described the incidents as "extremely dangerous" and "unacceptable". He also expressed deep concern over reports of a substantial Russian military build-up, including ground troops and ships in the eastern Mediterranean.

At the same time, Turkish President Tayyip Erdogan said he was losing patience with Russian violations of his country's …

According to U.S. military and administration officials, the U.S.-led coalition fighting ISIS has begun preparing to open a major front in northeastern Syria, aiming to put pressure on Raqqa, the terrorist group’s de facto capital.Two important steps were approved last week by President Obama to set the offensive in motion, officials said. Mr. Obama ordered the Pentagon, for the first time, to directly provide ammunition and perhaps some weapons to Syrian opposition forces on the ground.He also …

According to Turkish foreign ministry, Turkish F-16 fighter jets intercepted a Russian warplane that violated Turkey's air space.The incident occurred Saturday in the Yayladagi region of Turkey's southern Hatay province.

Turkish authorities called in the Russian ambassador and lodged a strong condemnation of the violation. "The Russian Federation will be responsible for any undesired incident that may occur," the foreign ministry warned.

Russia said the incident was a "navigational error" and …