ECB looking at all instruments, no decisions yet - Constancio

MADRID (Reuters) - The European Central Bank is looking at "all instruments including asset purchases" should it need to respond to a period of inflation being low for too long, ECB Vice President Vitor Constancio said on Thursday.

Speaking in Madrid, Constancio stressed that the ECB had not yet taken any concrete decisions on potential policy action.

"We will see, if the developments of inflation justify if action should be taken, but no decisions have been taken," he said.

"Monetary policy, when it reaches a situation of very low rates, becomes less effective, so we should be mindful of that," he added.

"We are in a new situation which requires more unconventional measures and we have indicated our position to consider those. We will continue to be mindful that and, as much as we can, we must deliver our mandate."

(Reporting by Paul Day; Writing by Paul Carrel)