Foreign minister Sergei Lavrov has accused the West of trying to use sanctions imposed on Moscow over the Ukraine crisis to seek "regime change" in Russia.

His comments followed remarks on Thursday by president Vladimir Putin, who said Moscow must guard against a "colour revolution", referring to protests that toppled leaders in former Soviet republics.

Sanctions have limited access to foreign capital for some of Russia's largest companies and banks, hit the defence and energy industries, and imposed asset freezes and travel bans on some of Putin's allies.