He said he is "not resigning" and will serve out his full term
US House Speaker Paul Ryan has announced he will leave Congress at the end of his term next year.
The Republican lawmaker told reporters of his plans to retire on Wednesday morning, following a closed meeting with members of his party.
He will serve out his term until January, when he will not stand for re-election.
Presenting the decision as a personal matter, the Wisconsin representative said he did not want to be a "weekend dad" as his children grew up.
He said: "The job provides incredible opportunities, but the truth is it’s easy for it to take over everything in your life. And you can't just let that happen.
"Because there are other things in life that can be fleeting as well: namely your time as a husband and a dad, which is the other great honour of my life.
"That’s why today I'm announcing that this year will be my last one as a member of the House.
"To be clear, I am not resigning. I intend to serve my full term as I was elected to do. But I will be retiring in January, leaving this majority in good hands with what I believe is a very bright future.
"It’s almost hard to believe, but I have been a member of Congress for almost two decades. This is my 20th year in Congress.
"My kids weren't even born when I was first elected. Our oldest was 13 years old when I became speaker.
"Now all three of our kids are teenagers. One thing I have learned about teenagers is their idea of an ideal weekend is not necessarily to spend all of their time with their parents.
"What I realise is if I am here for one more term, my kids will only have ever known me as a weekend dad. I just can't let that happen."
Concluding, Mr Ryan said: "I have to thank my colleagues for giving me this opportunity and this honour. I am really grateful for it.
"I also want to thank the people of southern Wisconsin for placing their trust in me as their representative for the past 20 years.
"I've tried to bring as much Wisconsin to Washington as I can in that time."
Shortly after the official announcement US President Donald Trump expressed his support for Mr Ryan.
"Speaker Paul Ryan is a truly good man, and while he will not be seeking re-election, he will leave a legacy of achievement that nobody can question," the President tweeted. "We are with you Paul!"
Speaker Paul Ryan is a truly good man, and while he will not be seeking re-election, he will leave a legacy of achievement that nobody can question. We are with you Paul!— Donald J. Trump (@realDonaldTrump) April 11, 2018
The public announcement was preceded by a closed door meeting with Republican representatives, in which Mr Ryan delivered his news in a sombre tone, reading directly from prepared notes.
"After nearly 20 years in the House, the speaker is proud of all that has been accomplished and is ready to devote more of his time to being a husband and a father," Brendan Buck, an adviser to Mr Ryan said in a statement.
"While he did not seek the position, he told his colleagues that serving as Speaker has been the professional honour of his life, and he thanked them for the trust they placed in him."
At a time of insecurity regarding their majority in the House of Representatives, the news will likely prompt a scramble among Republicans for the key post the retirement will leave empty.
Key figures including Kevin McCarthy and Steve Scalise declined to comment on whether they would seek to succeed Mr Ryan when quizzed by journalists.
"The only thing I'm focused on is doing whatever we can to keep the majority," Mr McCarthy, who withdrew a bid to become Speaker before Mr Ryan took the job, said.
While Mr Ryan appeared to share little in common with Donald Trump, he went on to played a central role in the current US administration.
More recently, Mr Ryan publicly urged Mr Trump to not proceed with proposed steel and aluminum tariffs, saying he was 'extremely worried' about the potential consequences.
President Trump has announced plans for a 25% tariff on steel imports and a 10% levy on aluminium, despite reports that his own advisers had urged him not to do so.
He said the move was in response to decades of "disgraceful" unfair trade policies.
His most significant achievement as Speaker was securing a US$1.5tn (€1.21tn) tax cut for US voters - one of the flagship victories of Donald Trump's term and a personal cause for Mr Ryan.
It was the largest overhaul of the US tax code in 31 years.
Mr Ryan posted this video about the issue back in 2017:
Additional reporting: IRN