Papua New Guinea PM steps down

Papua New Guinea's prime minister, Peter O'Neill, has formally resigned, he said on Wednesday.

"At 9.35 a.m. this morning I delivered to his excellency...the governor-general, my letter of resignation," he said in parliament at Port Moresby, the capital.

O'Neill had promised to resign on Sunday after a string of defections from his government plunged his leadership in to question last week and cost him his parliamentary majority.