Roughly a decade after the global financial crisis, central banks around the world may not have much left in their toolkit to boost the economy, according to the head of the Organisation for Economic Co-operation and Development.

Angel Gurria, OECD Secretary-General, made that comment as major central banks such as the U.S. Fed and the ECB recently signaled their readiness to cut interest rates.

Gurria told that the world “would be much worse off today” without central banks working to stimulate economic activity in the past decade. However, central banks “have run out of ammunition,” he said.

“Interest rates are at zero practically everywhere, or very close. And now we know interest rates are going to remain low for longer, that is as much as the central banks can do,” he said.

He added that it’s time fiscal policies play a bigger part in boosting economic activity. That means countries that can afford to spend more without jeopardizing their finances should do so, he explained.