BERLIN, June 6. /TASS/. NATO countries are seriously concerned over closer cooperation between Russia and Belarus, the alliance’s Secretary-General Jens Stoltenberg said in an interview with German newspaper Welt Am Sonntag.

"The allies are seriously concerned over closer cooperation between Moscow and Minsk over the past months," Stoltenberg said. According to him, Belarus "is becoming more dependent" on Russia.

"NATO is a defensive alliance. I don’t want to speculate a lot but we are vigilant and are very carefully watching the events in Belarus," the NATO chief said. "Of course, we are ready in a serious case to protect each participant of the alliance and protect it from any threat posed by Minsk and Moscow," he stated.

According to Stoltenberg, the Belarusian events will be discussed at the upcoming NATO summit in Brussels. The sides will review an agreement on partnership with Belarus - Partnership for Peace (PfP) - which has been frozen to a large extent, he noted.