MOSCOW - The United States uses anti-terrorism as a tool and a pretext to interfere in the internal affairs of other countries, Chairman of the Russian State Duma Vyacheslav Volodin has said.

This has undermined the role of state institutions and led to an increase in extremist sentiment, Volodin was quoted by TASS news agency on Sunday as saying.

"The Middle East and North Africa is an example. From 2011 to 2015, international terrorism in Syria grew to the scale of a 'terrorist pseudo-state'," he said at a conference of leaders of legislatures of Afghanistan, China, Iran, Pakistan, Russia and Turkey on the topic combating terrorism, while noting other the achievements of other countries in combating terrorism.

Most of Syria's territory was liberated from the terrorist group Islamic State thanks to the joint efforts of Russia, Iran and Turkey, Volodin said.