Microsoft founder and philanthropist Bill Gates has urged Australia to boost foreign aid following the country's announcement that it was delaying a pledge to increase overseas aid spending.

Gates made his plea during a speech in the capital Canberra on Tuesday. He says although Australia has been relatively generous, more money is needed for vital medicine and agricultural developments.

Australia said this month it was postponing by two years a long-standing pledge to increase its foreign aid spending to 0.5 percent of gross national income by 2015-16. Australia's foreign aid budget will increase to 0.37 percent in the next fiscal year.

Prime Minister Julia Gillard said Tuesday the country would spend another 80 million Australian dollars ($77 million) on polio eradication efforts. Australia had committed AU$50 million through 2014.