Rudd made the dramatic announcement at a media conference in Washington DC, which was beamed live to Australia saying "the simple truth is that I cannot continue to serve as foreign minister if I don`t have Prime Minister Gillard`s support", the Australian reported.
Rudd`s sudden resignation came after supporters of the Prime Minister said she was prepared to sack the Foreign Minister for disloyalty and amid signs that he was preparing for a showdown by challenging her for the leadership in the party`s upcoming caucus this week.
The foreign minister did not say whether he would challenge Gillard for leadership, but was intending to fly back to Australia to sort out his future.
But in his resignation speech, Rudd was highly critical of Labor Party`s move to oust him. "I can promise you this; there is no way that I will ever be a party to a stealth attack on a sitting prime minister elected by the people. We all know that what happened then was wrong and it must never happen again`, he said.
Australia`s Labor government has been torn by speculation about whether Rudd, who was ousted by Gillard as prime minister in mid-2010, would mount a bid to return to the top job.
He said in recent days sections of the Labor Party had publicly attacked his integrity and therefore his fitness to serve as a minister, in an apparent reference to quit notice served on him by former Labor Party leader Simon Crean. The globe-trotting diplomat said he would make a full statement on his future before parliament resumes on Monday.