In addition, Stefanovic said that "information exists" showing that these activities will become more intensive.
"An attempt is being made to influence Serbia's interests and reduce its influence, especially in the countries in the region where our compatriots live," he told the daily Vecernje Novosti on Wednesday.
Speaking after the first session of the Bureau for the Coordination of Security Services that he chaired in his capacity as secretary of the Council for National Security, Stefanovic said that the president of the republic and the government are "leading a policy of an independent Serbia" that "bothers many."
"No major power wants us to stay beyond their influence, even the countries in the region want to influence the process in Serbia, our economy, security. That is their legitimate desire. It is up to us, on the other hand, to prevent them - and we are doing that," Stefanovic said.
Asked when and how the government would resolve the status of the Russian-Serbian Humanitarian Center in Nis, Stefanovic said this was " a complex issue - the government will solve it in the coming period, taking into account all relevant information, possible reactions and assessments of what brings the least damage to the country."
In comments reported later on Wednesday, Stefanovic - asked to clarify his original statement - referred to the foreign services' activities in this country as "offensive" - and had this warning:
"Anyone who thinks they can use some more offensive intelligence activity to undermine our stability and security better think twice, before undertaking such activities - Serbia will know how to respond to all security challenges."