CHENGDU, China (Reuters) - The effectiveness of fiscal and monetary policies is diminishing and major economies should deepen coordination to promote sustainable, balanced growth, China's Finance Minister Lou Jiwei said on Saturday.

Lou was speaking at a meeting of G20 finance ministers and central bankers in the southwestern Chinese city of Chengdu.

(Reporting by Kevin Yao and Elias Glenn; Writing by John Ruwitch; Editing Jacqueline Wong)