WASHINGTON — House Speaker Paul D. Ryan said Wednesday he will not seek re-election in November, throwing an already fractious House into tumult and dealing another blow to Republican hopes of holding on to power in Congress.

“I think we have achieved a heck of a lot,” Ryan, R-Wis., said, pointing to tax cuts passed late last year and increased military spending. “I have given this job everything I have.”

He called the speaker’s position one of the “two greatest honors of my life,” the other being his role as husband and father. Ultimately, he said, he wanted to step down so that his teenage children would not only know him as a “weekend dad.”

“The truth is, it’s easy for (the job) to take over everything in your life,” Ryan said.

Ryan emphasized that he will serve out his full term and retire in January.

The announcement comes as Republicans face already serious prospects of losing their majority in the House in this fall’s midterm elections. Ryan has been a key fundraiser for Republican candidates, and his decision to call it quits is almost certain to be a demoralizing blow to the party’s candidates and donors.

Answering questions from reporters, Ryan said he was confident about Republican chances in November and that the prospect of becoming the minority did not play into his decision.

He also insisted that his departure would not affect the chances of other Republicans.

“If we do our jobs, we’re going to be fine,” he said. “We’re going to have a great record to run on.”

Ryan told members during a private meeting earlier Wednesday morning that “he had no idea what he’s going to do,” according to Rep. Ryan Costello, R-Pa.

Former House Speaker Newt Gingrich, in a telephone interview from Italy, said Ryan likely grew “tired” of the job.

“I think that he loves policy and does not particularly like managing and leading 240 Republicans and trying to cope with the Senate and the White House,” Gingrich said.

At 48, Ryan is young enough to go home, spend time with his family, earn some money, run for governor of Wisconsin, and then still forge a presidential campaign. “He’s got at least six presidential elections in front of him,” Gingrich said

Rep. Charlie Dent, R-Pa., who like Costello is also retiring after this term, said Ryan’s decision might cause other Republicans to announce retirements. “It might spur a few more,” Dent said.

Dent also voiced concern that Ryan’s departure will worsen internal party rivalries. “The last thing we need is a leadership battle,” Dent said.

Rep. Mark Meadows, who heads the rebellious House Freedom Caucus that often complicates the speaker’s job, agreed the party was probably heading into rockier waters.

“Does it create an uncertainty here? Yes, and with that uncertainty comes great opportunity,” Meadows said. He declined to comment on Ryan’s performance or say who the caucus would support as the next speaker, if Republicans keep the majority

Dent said Ryan was always a “reluctant speaker” who was frustrated by the GOP divisions and the Trump administration. “We can all read between the lines,” Dent said. “This is not an easy administration to deal with.”

But on Wednesday, Ryan had no criticism for Trump, saying he was “grateful” to Trump for “giving us this opportunity to do big things,” such as the tax-cut plan.

The speaker’s move came less than three years after he took the leadership post as a compromise candidate following the resignation of Ohio Rep. John A. Boehner. Ryan’s period as speaker will have been among the shortest in the past century.

Like Boehner’s before him, Ryan’s tenure was plagued by divisions within the GOP, some longstanding, others exacerbated by the election of Trump, whom Ryan first opposed, then eventually made an uneasy peace with.

Ryan scored one major victory last year, playing a central role in pushing through a tax-cut plan in December. In March, he was among the negotiators of a $1.3 trillion spending package that the president criticized but ultimately signed.

Senate Majority Leader Mitch McConnell, R-Ky., called Ryan a “transformational conservative leader” and “happy warrior.”

Ryan suffered a major defeat, however, when Congress rejected a measure he strongly backed to repeal the Affordable Care Act.

And Ryan’s other priorities, notably cutting back on Social Security and Medicare benefits to reduce long-term federal spending, were not popular even among many Republicans and were largely pushed aside by Trump.

Ryan criticized Trump during the campaign but accommodated him during his presidency, drawing fire for not speaking out against Trump’s attacks on the FBI, the Justice Department and special counsel Robert S Mueller III.

Ryan, the party’s vice presidential candidate in 2012, was 45 when he became speaker, the youngest to serve in that role since 1869.