FRANKFURT, Jan 19 (Reuters) - Rising inflation in the euro zone is primarily being driven by fluctuating energy prices and there are no signs it is sustainable, European Central Bank President Mario Draghi said on Thursday.

“There are no signs yet of a convincing upward trend in underlying inflation,” he told a news conference.

“Headline inflation is likely to pick up further in the near term, largely reflecting movements in the annual rate of change of energy prices. However, measures of underlying inflation are expected to rise more gradually over the medium term.”

The ECB has been pumping money into the euro zone economy in order to boost inflation, which at one point was threatening deflation.

The statement helped push the euro down against the dollar and it hit a 10-day low against sterling. (Writing by Jeremy Gaunt in LONDON; Editing by Louise Ireland)