The leaders of the Collective Security Treaty Organization (CSTO) will discuss ways to respond to NATO's growing activity on the borders of the military alliance during the summit to be held on December 26, CSTO Secretary General Nikolay Bordyuzha said in an interview with Izvestia newspaper.

"We must clearly understand what is happening around our borders, why NATO tightens arms, creates infrastructure. It has located additional four battalions in Eastern Europe. For what? We can not keep silent," Nikolay Bordyuzha said.

According to the Secretary General, it is important to understand how overall security situation changes and how to respond to these changes in order "not to be late."

In addition, the summit agenda also includes the issue of appointing the new CSTO Secretary General.

As the newspaper writes, Russian president's spokesman Dmitry Peskov confirmed that preparations for the summit of CSTO heads of state, which will be held in St. Petersburg on December 26, are underway.

CSTO includes Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia and Tajikistan.