Russia's President Vladimir Putin signed a decree on Wednesday allowing foreign investors with funds frozen in Russia to use them to buy blocked assets of Russians abroad.

As a result of sanctions imposed by the West over Russia's actions in Ukraine, more than 3.5 million Russians have frozen assets abroad worth around 1.5 trillion rubles ($16.3 billion).

Under the decree, Russia will allow citizens of what it deems "unfriendly" countries to buy frozen securities held abroad by Russians by using funds from special "type-C" accounts in Russia, which are otherwise effectively blocked.

Russia plans to unblock accounts worth about 100 billion rubles in the first phase.

The text of Putin's decree says it is being issued in response to actions by the United States and other countries and organizations that it calls "unfriendly and contradictory to international law."