March 23 (Reuters) - Russia plans to switch its gas sales to "unfriendly" countries to roubles, President Vladimir Putin said on Wednesday, responding to a freeze on Russia's assets by foreign nations over events in Ukraine that he said had destroyed Moscow's trust. European countries' dependence on Russian gas and other exports has been thrown into the spotlight since Russia sent tens of thousands of troops into Ukraine. “Russia will continue, of course, to supply natural gas in accordance with volumes and prices ... fixed in previously concluded contracts," Putin said at a televised meeting with top government ministers. "The...