A F16 jet fighter, foreground, is parked on the tarmac during the opening ceremony of NATO Trident Juncture exercise 2015, in Trapani, Italy, Monday, Oct. 19, 2015.

Kremlin spokesman Dmitry Peskov warned on Wednesday that the continuing expansion of the North Atlantic Treaty Organization (NATO) to the east would lead to retaliatory measures from Russia while U.S. played down Moscow’s fears.

Peskov made his statement after NATO military alliance on Wednesday invited Montenegro to join its ranks.

Peskov added to journalists that the sanctions that Russia had imposed on Turkey over a downed Russian plane were different from the ones the West had imposed on Russia over the Ukraine crisis, since Russia’s sanctions on Turkey were preventative and concerned the threat of terrorism.

U.S. Secretary of State John Kerry said after NATO invited Montenegro to join that the Atlantic organization is a defensive alliance and its decision to enlarge into the Balkans is not directed at Russia or any other nation.

“NATO is not a threat to anyone … it is a defensive alliance, it is simply meant to provide security,” Kerry told a news conference. “It is not focused on Russia or anyone else.”

Kerry also said NATO members stand ready to step up military efforts against ISIS.

Kerry said he asked foreign ministers from the 27 other members of the alliance to do more to strike at ISIS’s core in Iraq and Syria and strangle its international networks.

He said several countries are bringing more to the battle or will do soon. Speaking Wednesday at NATO headquarters in Brussels, Kerry didn’t outline any new commitments specifically.

Germany recently approved sending forces and materiel for non-combat support roles near the Middle East. A British vote is expected later Wednesday on expanding that country’s airstrikes against ISIS into Syria.

Kerry said other countries would come forward with new plans after further discussions at home.

Related articles across the web

• Bickering in the Balkans: Officials clash over migrants
• EU braces for turbulent summit after divisive deal on refugee quotas
• Orban mobilizes Hungary's troops, prisoners, jobless to fence out migrants
• Border tensions rise between Croatia and Serbia
• Russia-Israel military alliance in Syria is a breakthrough
• Border Tensions Rise Between Croatia and Serbia
• It's Not a Putin-Obama Poker Game that's happening
• Border tensions rise between Croatia and Serbia
• Border tensions rise between Croatia and Serbia
• Border tensions rise between Croatia and Serbia