SYDNEY, May 26 (Xinhua) -- Embattled Papua New Guinea Prime Minister Peter O'Neill has announced his resignation at a media conference in the capital city of Port Moresby on Sunday, after a series of ministers defected from his cabinet.

As a pending leadership challenge scheduled for Monday is expected to gain the support of a majority of MP's, O'Neill cited the parliament's "need for change" as the reason for his departure.

O'Neill handed over the leadership to former Prime Minister Julius Chan.