MOSCOW — President Vladimir V. Putin appeared on Wednesday to throw his support behind a plan to isolate the Internet in Russia from the rest of the World Wide Web, but said the Russian government was “not even considering” censoring Internet sites.

In a speech to the Russian National Security Council, Mr. Putin said the plan was intended to build a backup system to keep websites in the Russian domains — those ending in .ru and .rf — online in a national emergency.

Mr. Putin said other countries had taken to using the Internet “for not only economic, but military and political goals” and said information security was a priority for the country.

The Russian news media has labeled the plan, some details of which were reported last month by Vedomosti, a Russian daily, a “kill switch” for the Internet, or Russia’s answer to the “Great Firewall” put up by the Chinese.