Russia's Central Bank signalled for the first time on Friday that it could tighten policies in response to a ruble plunge that has outpaced all other emerging currencies.
The Central Bank matched market expectations by leaving its key interest rate unchanged at 5.50 percent for the 16th consecutive month.
It based its decision on slowing inflation and disappointing growth.
But the bank went out of its way to caution that inflation still remained a "source of uncertainty" owing to the ruble's drop against the dollar that has exceeded seven percent since the start of the year.
If the negative effects of the currency collapse widen, "the likelihood rises of inflation deviating from its medium-term targets," it added.
"In this case, the Central Bank will be ready to tighten its monetary policy."
The Central Bank's guidance was issued moments after the ruble established an historic low against the euro in early morning trading on the Moscow Exchange.
The Russian currency made a slight recovery after the statement was issued and stood at 48.04 against the euro at 1430 GMT -- stronger than the 48.39 inter-day low it hit on January 30.
The dollar was worth 35.07 rubles and also within striking distance of its historic high.
Analysts at VTB Capital estimate that emerging market currencies have lost 1.5 percent of their value against the dollar since the start of they year.
This makes the ruble the emerging world's worst performer. The South African rand is second-from-bottom on the list with losses of 4.5 percent.
Economists have concluded that the Central Bank purchased more than $8 billion (5.8 billion euros) of foreign currency on the Moscow market in January in an effort to stem the ruble fall.
This was the largest volume since the closing months of Russia's 2008-2009 economic collapse.
Emerging markets have suffered from the Federal Reserve's launch of monetary tightening measures that have seen investors flee riskier assets in anticipation of higher rates of return on US bonds.
- 'Statement of intent' -
Some policy makers in the Kremlin had spent recent months advocating an interest rate cut that could spur growth from just 1.3 percent last year -- the second-slowest pace of Vladimir Putin's 14-year rule as both president and prime minister.
Many thus read Friday's statement as a vow by Russia's regulators to ignore political pressure and redouble their focus on their new mandate of fighting inflation risks.
"Today’s meeting represents a statement of intent by the Central Bank and will dash any remaining hopes (including from within the Kremlin) that the Bank might loosen policy aggressively in the face of continued economic weakness," said Neil Shearing of the Capital Economic consultancy.
"This in turn will shift the emphasis back on to the government, and the need for a new wave of economic reforms that is now needed to revive growth."
But market players remained apprehensive and several complained that the Central Bank did not make its commitment to a stronger ruble explicit enough.
"The market has reached a consensus that the Central Bank does not intend to support the national currency by raising key interest rates," Moscow's Nord Capital financial advisory said in a research note.
Its economists accused regulators "of fuelling market fears and then squandering resources on currency interventions."