The European Central Bank needs more time to assess if it will have to beef up its €1 trillion plus asset-buying programme, ECB President Mario Draghi said.
His comments confounded some expectations that the bank was ready to expand quantitative easing.
Mr Draghi made his comments at the European Parliament's Committee on Economic and Monetary Affairs.
He said the bank was ready to act but needed more evidence to see if the emerging market slowdown, the euro's firming and the fall in commodity prices would hijack inflation from its projected path.
"The asset purchase programme has sufficient in-built flexibility," Draghi said in prepared remarks.
"We will adjust its size, composition and duration as appropriate, if more monetary policy impulse should become necessary," he said.
"More time is needed to determine in particular whether the loss of growth momentum in emerging markets is of a temporary or permanent nature and to assess the driving forces behind the drop in the international price of commodities and behind the recent episodes of severe financial turbulence," Draghi said.
Draghi said it will take somewhat longer than previously anticipated for inflation to stabilise around the ECB's target of just under 2%.
His comments come after the US Federal Reserve left rates on hold last week on concerns about China's economic slowdown, renewed financial market volatility and sluggish inflation at home.
Though the Fed left open the door to a hike later in the year, particularly as the US economy approaches full employment, its decision raised concerns that the emerging market slowdown, led by poor industrial demand in China, could have a bigger impact on advanced economies than earlier seen.
PMI data today showed activity in China's factory sector unexpectedly shrank to a six and a half year low in September, just the latest in a string of weak data for the world's second-largest economy.
Chinese factory output sank to its lowest since the global financial crisis and soft orders suggested more weakness ahead, reinforcing expectations that growth could dip below dip below 7% for the first time since the global crisis. That could trigger more monetary and fiscal stimulus.
China's slowdown has depressed global commodity prices, a particular worry for the ECB as inflation, now at a barely visible 0.1% could miss the bank's target of almost 2% for years to come.
Europe appears relatively resilient for now, however, with September PMI data showing only a small drop from relatively high levels, indicating that emerging market weakness is not derailing the euro zone's slow but steady recovery.
