In rare public criticism of the close ally, Mr Hockey said Australia - the current chair of the Group of 20 major economies - was "deeply disappointed" by the failure of a 2010 IMF reform plan to come into effect and said the blame lay "firmly and uniquely" with the US Congress.

"The United States drove the reform agenda of the IMF and the United States Congress is now the biggest impediment to that reform being delivered," Mr Hockey said on the sidelines of annual IMF/World Bank spring meetings in Washington.

"It has done considerable damage to the standing of the United States, and I don't think that serves anyone's interest," he told a forum hosted by Johns Hopkins University.

"As a close friend of the United States, we will always call it as we see it in Australia."

Voicing fear that reforms were now "highly uncertain" to take place, Mr Hockey said he was calling a meeting on the issue on Friday between the Group of 20 and the International Monetary and Financial Committee, which advises the IMF Board of Governors.

The reforms, approved by the Board of Governors in December 2010, would double the overall quota that nations provide to fund the IMF and would give a larger voice to emerging economies.

Mr Hockey said the reform package was critical to ensuring that the IMF remained "legitimate, effective and central" at a time of high needs in the global economy.

President Barack Obama has urged Congress to approve the reforms, which would not require immediate new funding as the United States would shift its contribution away from an IMF crisis fund that is winding down.

Politicians from the rival Republican Party have opposed the reforms, with arch-conservative Senator Ted Cruz saying that the package would unfairly raise US contributions while undermining its influence.

AFP