US House Speaker Paul Ryan has announced that he will not seek re-election in November and will retire in January after serving his full term.
- Mr Ryan says he's leaving with strong accomplishments
- There's concern Republicans will struggle to retain the House in November
- The announcement could also impact campaign fundraising efforts
The top Republican in Congress said he had accomplished a "heckuva lot" and cast the decision as a personal one, saying he did not want his children growing up with a "weekend dad".
Mr Ryan said he believed he is leaving with strong accomplishments that his party can sell to voters ahead of November congressional elections.
"I have given this job everything I have," he said.
"We're going to have a great record to run on."
The departure of 48-year-old Mr Ryan could complicate Republican Party efforts to retain the House in November, when candidates may be dragged down by the unpopularity of US President Donald Trump.
The announcement of his departure months before the election will give potential candidates for House Republican leadership positions plenty of time to campaign for support.
Reports of Mr Ryan's departure have circulated for months. Politico reported in December that Mr Ryan told confidants he would like to retire after the 2018 congressional elections.
Friends said Mr Ryan, a long-time champion of tax reform, was ready to step down after passing a tax reform bill, according to the Axios news site.
The tax bill was Mr Trump's first major legislative victory since he took office in January 2017, despite being helped by Republican control of Congress.
Decision may hit Republican campaign funds
Mr Ryan, who has had a difficult relationship with Mr Trump, thanked the President for giving him the chance to move the GOP ahead.
Mr Trump praised Mr Ryan on Twitter, describing him as a "truly good man" who will "leave a legacy of achievement".
Mr Ryan was elected to the US House of Representatives in 1998 from Wisconsin at age 28 and was quickly pegged as a Republican rising star.
He became 2012 Republican presidential candidate Mitt Romney's vice-presidential running mate, but Mr Romney was beaten by Democratic president Barack Obama.
In Congress, Mr Ryan earned a reputation as a fiscal policy expert, serving as chairman of the House Budget Committee from 2011 until 2015, but as Speaker was a driving force behind a Republican tax overhaul passed by Congress last year that is projected to balloon the federal deficit.
Politicians had expected Mr Ryan might leave Congress if Republicans lose the House in November.
The early announcement could have an impact on Mr Ryan's ability to raise campaign funds for Republican candidates.
More than three dozen House Republicans have said they are retiring, or running for another office, or resigning.
Democrats need to win 23 seats in the November elections to retake a majority in the House, which Republicans have controlled since 2011.
Democrats believe that voter concerns over rising medical costs and Republican plans to cut Medicare and Medicaid will assist them in their fight to retake the House.