International Monetary Fund chief Christine Lagarde lashed out Thursday at banks for resisting financial reforms, warning that delay in implementation could stall the global economic recovery.

"Some reforms are meeting strong resistance," Lagarde, the managing director of the Washington-based institution, said in a speech in Toronto.

"There are many vested interests working against change and pushback is intensifying," she said.

"It is interesting how some banks say the new regulations will be too burdensome, and yet are prepared to spend hundreds of millions of dollars lobbying to kill them."

The IMF chief said ongoing reforms of the international banking sector are "heading in the right direction, but they have not yet delivered a safer financial system."

She warned that banking systems are still "overly complex," banking assets are still concentrated, some banks continue to rely too much on wholesale funding and many institutions are still "too-important-to-fail."

But Lagarde said 75 percent of the reforms are close to being implemented.