The European Central Bank could expand its monetary policy toolkit if needed to respond to threats to price stability, and must ensure the euro zone economy does not enter a downward spiral, ECB Executive Board member Peter Praet said on Wednesday.

"We have an objective: price stability," Praet, who is in charge of the economics portfolio on the ECB's six-member executive board, told a conference in Washington.

"If that objective is at risk, we have the possibility ... to expand the range of (monetary policy) instruments if we think it's necessary for that objective," he said.

(Reporting by Jason Lange)