McCullum explains retirement decision

New Zealand captain Brendon McCullum has confirmed he will retire from international cricket following the Test series against Australia early next year.

The Black Caps will host the Aussies for Tests in Wellington and Christchurch in February, a two-match series that will be McCullum's international swansong.

The 34-year-old said his decision to announce his retirement now was borne of circumstance; the squads for the World T20 in March and April must be announced before his intended retirement date, and he was keen to avoid any speculation.

McCullum will be remembered as one of the greats of NZ cricket // Getty

"Ideally, I would have preferred to wait until after the (second) Test in Christchurch to make this news public," McCullum said.

"However, the schedule for naming the ICC World T20 squads means I could not have managed this without causing a lot of confusion and speculation – something I was keen to avoid.

"I’ve loved my opportunity to play for, and captain the Black Caps, but all good things have to come to an end, and I’m just grateful for the wonderful experience of playing for my country."

With McCullum to miss the World T20, the Black Caps have confirmed that Kane Williamson will captain the side at the tournament in India.

The first Test against Australia in Wellington from February 12 will be McCullum's 100th - which he has played consecutively since his debut against South Africa in 2004 - but he will fall short of Daniel Vettori's NZ record of 113 Tests.

The big-hitting right-hander also needs just one more six in Test cricket to pass Adam Gilchrist's all time record.

Quick Single: 'It's the only record I actually care about'

McCullum's final game for the Black Caps will be the second Test at Christchurch's Hagley Park from February 20.

A dashing batsman and former wicketkeeper, McCullum will be remembered as one of the most destructive players of his era.

WATCH: McCullum slams 80 at the Gabba

The right-hander has 11 Test centuries to his name, including a triple-century against India, plus five ODI tons and two in T20 cricket.

More than the runs McCullum has scored, it's the way he's scored them that will define his legacy. His current ODI career strike rate is an incredible 95 from 254 matches, while he has blasted a total of 381 sixes for his country across all formats of the game.

Since taking over the captaincy in all three formats in late 2012, McCullum has guided New Zealand to 11 Test wins to be equal second with Geoff Howarth and behind Stephen Fleming (28).

He also led New Zealand to their first World Cup final at this year's 50-over tournament.

Before McCullum says farewell, NZ will face white ball assignments against Sri Lanka, Pakistan and Australia before the Test series against the Aussies.

"There’s a time and place for reflection, and that’s at the end of your career," he said.

"For now, I’ll be giving all my attention to helping the team focus on what’s coming up over the next few weeks – and making sure we’re in the best possible shape for what’s going to be a very challenging summer."

Star batsman Williamson - who yesterday was crowned the world's No.1 ranked batsman - is expected to take over the captaincy on a full-time basis.

McCullum in full flight against Australia // Getty

McCullum's retirement will mean he is now available to link with KFC Big Bash League franchise Brisbane Heat for the next two seasons. He signed a three-year deal with the Heat earlier this year, but his Black Caps commitments mean he is unavailable for BBL|05.

He will also continue his Indian Premier League career in 2016; he was signed by new franchise Rajkot just last week for $1.5 million AUD after his previous team Chennai Super Kings were suspended following a match-fixing probe.

NZC chief executive David White praised McCullum, adding the time would come to fully celebrate his amazing career.

"We’ll celebrate Brendon’s wonderful contribution to New Zealand and world cricket at the end of the season," White said.

"For now, we want to help him prepare for the upcoming seven weeks with the minimum of distractions."

Speaking to cricket.com.au earlier in the summer, McCullum was philosophical when asked about when the end would come.

He added he was confident that several Black Caps players had leadership qualities to replace him when he calls it quits.

Exclusive: McCullum discusses NZ's 'nice guy' tag

"Whenever I am finished, or whenever I am removed from the post I know there is some young leaders within this group who will be able to drive this team to even greater results and standards than what we’ve been able to achieve of late," he said in November.

"I haven’t come up with any decision yet and normally what happens in this game is it’s not your decision anyway.

"So we’ll just wait and see what happens.

Quick Single: Rejuvenated McCullum ponders the end

"I’m loving being part of this group at the moment, I’m very privileged to be able to captain these guys, this group of men who I’d be pretty much prepared to do anything for.

Exclusive: The moment NZ turned their fortunes around

"They’re great guys and I’m very, very lucky to be a part of it.

"Never in my wildest dreams did I think I would play for as long as I have, let alone in the final stage of (my) career to be part of a team that you always hoped would be how things would run."

Brendon McCullum: The Numbers