Mr Joyce resumes the position he held from February 2016 to February 2018, when he resigned amid revelations he was expecting a child with a former staffer.
He said his three years on the backbench had led him to reflect on his impact on others.
“Well, I acknowledge my faults,” he said.
“And I resigned as I should and I did.
“I’ve spent three years on the backbench and you know, I hope I come back a better person.
“I don’t walk away from the fact that you have to have time to consider, not only the effect on yourself, but more importantly, the effect on others.
“I’ve done that. I don’t want to dwell on the personal, except to say hopefully one learns from their mistakes and makes a better person of themselves.”
Mr Joyce said Mr McCormack had conducted himself with dignity “right to the end”.
The spill motion was moved by Nationals Senator Matt Canavan this morning and comes after days of speculation over the leadership of the party.
David Littleproud will remain as deputy leader of the party, with his position not contested.
He too thanked Mr McCormack and quickly moved to setting the party’s path forward.
“But today, we now have to draw a line in the sand and get on with the job,” he said.
“It’s as simple as that. We need to come together and unify, doing the things that we do best, which is looking after regional Australians.
“They’ve had enough kicks in the guts.
“It’s time now to help them out of the fires, the droughts, the cyclones and get them back up and going and I think that it’s important that the National Party gets on with that job and those men and women and the children there, who put ourselves here, to give them their fair share.”
Mr McCormack said he respected the party room’s decision to remove him as leader.
“I wish Barnaby Joyce all the best as leader of the National Party,” Mr McCormack told reporters at Parliament House.
“I have been honoured to serve the National Party as its leader the past three years.
“I have been privileged and humbled to do that, the National Party has been the party of regional people for more than 100 years.
“It will go on irrespective of who is the leader, to be that party with the regional voice, the party that looks after the interest and concerns, and cares of regional people.
“The National Party has always been more than the individual, and that’s why I very much respect the decision taken by my colleagues today.
“I thank my colleagues for giving me the privilege of serving them as their leader for the past three years.”
Mr McCormack called on his colleagues to stop backgrounding and to “have the guts and gumption to put your name to it”.
Reports of a spill gained momentum over the weekend after a story in the Australian Financial Review claimed Mr Joyce was counting the numbers for a tilt at the leadership.
“Don’t background against your colleagues,” he said.
“It is not good for the Parliament.
“It is not good for democracy.
“If you are going to say something, put your name to it.
“I have always done that, always been upfront and honest and each and every one of you know that.”
He said he would consider his future as an MP before the next election, noting he had already been preselected as the Member for Riverina.
Mr McCormack deferred when asked whether Mr Joyce’s high-profile relationship with his former staffer Vikki Campion would damage the Nationals vote with women.
“You would have to ask women in regional Australia that,” he said.
“I am a man in regional Australia. You would have to ask a woman in regional Australia.
“Again, Barnaby has been elected democratically according to party traditions and all of the rest – it is not party tradition because we don’t normally do this – but by convention he has been elected.
“He’s got more numbers than me this morning. Good luck to him. I respect that.”
Earlier, Nationals whip Damian Drum revealed the outcome of the ballot in a brief media conference.
“There was a spill motion put forward. (The) spill motion was carried,” Mr Drum said.
“We had an election and Barnaby Joyce has been elected leader of the National Party at a federal level.
“He has to go through a process now to be sworn in, to have all the conversations, to talk to the Prime Minister, and effectively get on with the job of representing our people.”
Mr Drum described the Nationals as “the most democratic party in Australia”.
Mr Morrison is in quarantine at The Lodge but will resume his duties remotely.
Joyce backs party room on climate divisions
Mr Joyce said he would be guided by the party room on whether the Coalition should adopt a climate policy of net zero emissions by 2050.
As a backbencher, Mr Joyce had threatened to cross the floor if the government did so.
“I will be guided by my party room,” he said.
“It is not Barnaby policy – it’s Nationals policy.
“And Nationals policy is what I will be an advocate for and if the National party room believes that the best deal for regional Australia is to make sure that we secure their jobs, is to make sure that we secure their industries, is to clearly understand the dynamics of an Australian economy, as to opposed to a Danish one or a German one, if that’s the view of the National party room, that’s the view that I’ll support.”
Labor hits out at ‘self-indulgent’ government
Opposition Leader Anthony Albanese slammed the timing of the spill and used a media conference to highlight what he says are differences in Labor and Coalition policy, particularly around climate change.
“This government had just two jobs this year,” Mr Albanese said.
“They had to roll out the vaccine, and they had to fix national quarantine.
“Now instead of rolling out the vaccine to the Australian people, they just concentrated on rolling each other.
“The rolling of Michael McCormack, a decent human being, by Barnaby Joyce represents the sixth combination of prime minister and deputy prime minister under the eight long years of this government.
“It’s a vote of no-confidence in their own government.
“The fact is, if you want to end this circus, it’s time to end this government.
“I’ve seen governments be self-indulgent before and get punished.
“This is a government that is being self-indulgent at a time of the pandemic.
‘”The last time there was a spill was in the middle of the bushfire crisis – this time it’s in the middle of a pandemic.”