NATO is going to conduct its biggest military exercises in 10 years. The exercises, to be held in October and November, will have a specific focus on fighting Islamic State militants, the alliance says.

NATO describes the Commonwealth Trident Juncture 2015 as one of its most difficult training plans. The exercises will include an “artificial threat scenario” on sea, on land and in the air.

Russia is among the countries invited to observe the exercises. Russia has, however, been critical about NATO’s military buildup in its neighboring countries.

The Russian Foreign Ministry said NATO was developing military establishments “under the false pretext of alleged aggressive behavior” by Russia. The ministry added that the military drills were accompanied by “unfriendly and malicious” rhetoric, Russia Today reported.  

Russian President Vladimir Putin said in June that his country was not threatening anyone. He said Russia was willing “to resolve all conflict situations through political means, with respect toward international law and other nations’ interests.”

Gen. Hans-Lothar Domrose said the NATO forces would work in a huge training area and focus on multiple threats and on speed at the same time. "We cannot choose between the eastern threat and the southern threat, we have to train for both," Reuters quoted the commander of the NATO military command in Brunssum, the Netherlands.

Domrose also said it was not possible to choose between "the southern threat" and "the eastern threat." That is why the forces will have to train for both, he said. About 36,000 personnel from more than 30 countries are going to take part in the exercises.

The participating countries include non-NATO members Austria and Sweden. The exercises will take place in the Mediterranean Sea as well as in Portugal, Spain and Italy from Oct. 3 to Nov. 6.