Treasurer Joe Hockey believes global growth would much be slower today if it had not been for Australia's G20 leadership last year that saw world leaders agree to a two per cent growth target.

He has also warned that the Chinese government will not renegotiate its free trade agreement with Australia if Labor successfully blocks the agreement, following similar warnings from Trade Minister Andrew Robb.

Speaking after a two-day G20 finance ministers meeting in Turkey on Sunday, Mr Hockey said global leaders were frustrated by the fact that the International Monetary Fund had downgraded its world growth outlook this year.

"(But) world growth would be lower if not for our leadership and determination last year to have a two per cent target and to roll out a global infrastructure initiative," Mr Hockey said.