SYDNEY (AFP) - G20 host Australia on Saturday urged better advance notice of policy changes by central banks to avoid shockwaves for emerging economies at a meeting of finance ministers where rifts over United States monetary policy loomed large.

Australian Treasurer Joe Hockey said he wants the summit to stay focused on ways to stimulate growth and create jobs in the aftermath of the 2008 financial crisis, adding he was confident of tangible results.

"I must say there is tremendous goodwill in all the meetings I have attended," he told reporters before Saturday's meetings began.

But the fallout being felt by emerging economies, which have suffered sharp capital outflows and losses to their currencies as a by-product of the Federal Reserve easing back its mammoth stimulus programme, remains a lightning rod issue.

Countries led by Indonesia and South Africa, which is not attending the Sydney meeting along with Mexico and Brazil, have called on the US to provide more clarity on its wind-back and better communication to subdue the impacts on emerging markets.

US Treasury chief Jacob Lew said the US had to act in its own best interests.

"My focus as US treasury secretary has to be on the core strength of the US economy and I think the world economy does better when the US economy is doing well," he was cited as saying on Friday by the Australian Financial Review.