"The Russian President had telephone conversations with Kyrgyz President Sadyr Zhaparov, Belarusian President Alexander Lukashenko, Tajik President Emomali Rahmon, and Armenian Prime Minister Nikol Pashinyan," Xinhua news agency quoted Kremlin as saying.
Putin also spoke by phone several times with Kazakh President Kassym-Jomart Tokayev, it said.
"The discussion focused on the developments in Kazakhstan and joint actions under the CSTO mandate to combat international terrorism, restore order and protect the country's citizens," it added.
Meanwhile, since the launch of the CSTO peacekeeping operation, Russian Defense Minister Sergei Shoigu has been regularly reporting to Putin on the progress of transfer of peacekeeping forces to Kazakhstan and the completion of assigned tasks, the statement said.
Violent protests in Kazakhstan have caused multiple deaths over the past days, according to various reports.
Tokayev accepted the government's resignation on Wednesday, and has sought help from the CSTO.
A joint CSTO peacekeeping force has arrived in Kazakhstan to take part in maintaining order, the Kazakh presidential press service said Friday, adding that they came only for a limited time to ensure the protection of strategic facilities.
The peacekeeping forces include troops from Russia, Belarus, Armenia, Tajikistan and Kyrgyzstan, the CSTO said in a statement on its website.