Russia's central bank says it will buy $100 million to $200 million a day in the market to replenish its foreign currency reserves.
The bank made the announcement on May 14 after Russia's currency reserves slumped $120 billion in less than a year to its lowest level since at least 2008.
The reserves started falling in July 2014 as policy makers sought to prop up the ruble weighed down by U.S. and European sanctions over the Ukraine crisis.
Last year, Russia spent almost $90 billion of its reserves before abandoning its managed exchange-rate policy in November as falling oil prices exacerbated the ruble's retreat against the dollar.
But the ruble has rebounded more than 20 percent this year amid a jump in oil prices and as a cease-fire agreement in eastern Ukraine reduced the likelihood that sanctions will be deepened.