WELLINGTON - New Zealand Finance Minister Bill English was confirmed as the country's new prime minister on Monday, as expected, a week after John Key announced his surprise resignation after eight years in the role.

A file picture dated 23 February 2014 shows New Zealand Deputy Prime Minister and Minister for Finance, Bill English, posing for a graph during the G20 Finance Ministers and Central Bank Governors meeting in Sydney, Australia. [Photo/Agencies]

English, who was the sole contender for the job, announced Social Housing Minister Paula Bennett as the deputy leader, following a special caucus meeting of the ruling centre-right National Party.

English, who will be sworn in later in the day, has already lined up senior cabinet minister Steven Joyce, the minister for economic development, to replace him in the finance ministry.

He is expected to announce further cabinet changes in the coming weeks and has also signalled a "stocktake" on policy.

"I am both excited and humbled by this opportunity," English, who comes from a conservative, Catholic family in New Zealand's south, told reporters after the meeting.

English, who 13 years ago oversaw a disastrous election loss for the National Party to the centre-left Labour Party, takes the reins of a country in good economic shape compared to much of the developed world.

On Monday, Moody's said it expects New Zealand to remain among the fastest growing of triple-A rated economies.

English has held several ministerial posts across education, health and finance since he joined parliament in 1990.

As finance minister, his key policies included moves to partly privatize several state-owned energy firms and Air New Zealand, cutting personal tax and corporate tax rates and increasing the goods and services tax.