TROIA, Portugal (AP) -- NATO's secretary-general sounded the alarm Thursday over the build-up of Russian military forces from the Baltic Sea to the Mediterranean and called on the U.S.-led alliance to come up with a response.
Jens Stoltenberg said the Russians have concentrated military forces in Kaliningrad, the Black Sea and the eastern Mediterranean, where they are assisting beleaguered Syrian President Bashar al-Assad.
Speaking at a news conference during NATO war games in Portugal, Stoltenberg said experts believe the Russian build-ups could lead to Moscow's ability to limit the access of the United States and its allies to certain regions.
"We have to be sure that we are able to overcome these capabilities, so we can reinforce, so we can move and we can deploy forces if needed," Stoltenberg said. The NATO chief said this challenge was now "the question on our agenda."
Earlier in the day, NATO put some of its naval and special forces capabilities on display at this naval base south of Lisbon, and also showcased the ability of armed forces from its 28 member nations to work together.
As Stoltenberg and other VIP guests looked on, British and Spanish marines riding landing craft stormed a beach. Portuguese marines fast-roped from a helicopter onto the bow of a ship, simulating the retaking of a vessel seized by terrorists or pirates. The Portuguese were reinforced by units from Polish special forces, who also checked for the presence of chemical, biological or nuclear hazards.
For the past three weeks, more than 36,000 personnel from NATO allies and partner nations have been taking part in exercises across a swath of southern Europe stretching from Portugal to Italy. The maneuvers, code-named Trident Juncture, are being held to hone NATO's ability to respond to a range of new security threats, including a more assertive Russia and Muslim terrorist groups like the Islamic State group.