Image copyright Getty Images Image caption Andrew Little led the Labour Party for nearly three years

Andrew Little, the head of New Zealand's main opposition Labour Party, has resigned - less than two months before the country's general elections.

"Recent poll results have been disappointing. As leader, I must take responsibility for these results," Mr Little said.

Deputy leader Jacinda Ardern, 37, has been named as his successor, promising to "run the campaign of our lives".

New Zealand is due to hold the elections on 23 September.

Announcing his resignation, Mr Little, 52, said he hoped a fresh leadership team could boost the centre-left party's campaign ahead of the elections.

Recent opinion polls show that the party's support has dropped to about 23-24% - the worst in many years.

Mr Little led the Labour Party for nearly three years.

New Zealand is currently governed by the centre-right National Party-led coalition under Prime Minister Bill English.

Ms Ardern tweeted that she felt "privileged and honoured to have been elected leader" and thanked Mr Little for "his huge work and his leadership".

She named Kelvin Davis as her deputy.