President Vladimir Putin says no country can "intimidate" or "isolate" Russia, after the West imposed new sanctions on Moscow over the Ukraine crisis.

"Of course, no one will be able to intimidate us, or contain and isolate Russia. No one has ever been able to and no one ever will," Putin said in a speech on Saturday.

Putin said Russia must be prepared to "go through certain difficulties and always give an adequate response to all the threats to its sovereignty, stability and the unity of society".

On Friday, the European Union and the United States boosted sanctions against Crimea over its annexation by Russia in March.

In moves coordinated with Washington, the EU agreed to ban all investment in Crimea and cruise ships from its ports.