There are no signs for optimism in U.S.-Russia ties, warned the head of Moscow's International Affairs Committee.
The Russian jets didn't broadcast the proper codes to air traffic control.
Turkey's relationship with the U.S. has been strained for months.
The S-400 deal, reportedly worth about $2.5 billion, has caused concern in the West because Turkey is a member of NATO.
The Kremlin has expressed concern over the missile shield the U.S. provides in Eastern Europe, near Russia's western border.
The alliance is concerned about Moscow's presence near undersea communication lines.
The EU cannot afford to become indifferent to threats to the rule of law among its members.
Undersea lines across the Atlantic are crucial for communication and trillion-dollar trade, but Russian ships have reportedly been moving near known cable routes.
With the establishment of a new Cyber Operations Center, NATO has launched a new, historic campaign of electronic warfare.
Beijing's man in Moscow said the key to Russia and China's relationship was their mutual abandonment of Cold War logic.
Western observers consider Russia's role in Egypt, Libya and Syria as a challenge to NATO, which tried to overthrow leaders in all three Mediterranean states.
Russia's increasing military activity and NATO's mobilization of troops across Europe have put nonaligned Finland in a tough spot.
The U.S secretary of state said, "There is broad consensus among all the NATO members that there is no normalization of dialogue with Russia today."
German Foreign Minister Sigmar Gabriel is deeply critical of Trump's stance on Iran and North Korea and says Europe must take its own path.
"NATO needs to take note of the enormity of China's influence," a former NATO and U.S. military leader said.
Turkey has developed a cloth that could make soldiers invisible to radar.
Russia's Baltic fleet has put its newest rockets and artillery on display in the middle of Kaliningrad.
"As power is shifting away from the West toward Asia, the West's ability to influence the agenda on a global scale is expected to be reduced," the latest NATO report found.
"Everything is fine, just perfect. I congratulate the aircraft builders and I think we will deliver good news to the defense ministry," Putin said of the new TU-160M2.
The U.S. currently has around 62,000 troops in Europe.
Britain's foreign secretary will visit Moscow in the coming months to address the country's relationship with Vladimir Putin.
Germany, France and 21 other European states have voted to plan their defenses together and avoid wasteful spending.
Veterans are more likely to be jobless and they have suicide rates higher than the national average.
NATO "has intensified operative and combat training activities, including nuclear weapons use procedures," Russian Defense Minister Sergey Shoigu said.
Lithuania's defense minister said NATO states "need to address" permanent anti-aircraft power across the Baltic states and Poland to counter Russia.