At 0705 GMT, the rouble was 0.24 percent weaker against the dollar at 57.58 and was steady at 70.57 versus the euro.

Russia's finance ministry, which started buying foreign currency for its reserves in February 2017, said on Wednesday it would buy 25 percent more dollars and other currencies in April than in March.

A further slide in relations between Russia and the West also dragged the rouble lower after the Organisation for the Prohibition of Chemical Weapons dismissed a call by Moscow for a joint inquiry into the poisoning of a former Russian double agent in England.

The United States is also planning to announce further sanctions against some Russian oligarchs this week under a law targeting Moscow for alleged meddling in the 2016 US election, sources familiar with the matter told Reuters on Wednesday.

VTB analysts said higher prices for oil, Russia's main export, had helped support the Russian currency.

Benchmark Brent crude oil was up 0.32 percent at $68.24 a barrel, buoyed by the US government data showing a surprise drawdown in crude stockpiles.

Russian stock indexes tracker oil prices higher.

The dollar-denominated RTS index was up 0.5 percent to 1,246.60 points. The rouble-based MOEX Russian index was 0.58 percent higher at 2,277.01 points.

Sources said on Wednesday the Moscow Stock Exchange is discussing giving brokers by the end of this year remote access to shares in 50 Western companies trading on other exchanges.