House Budget Committee Chairman Paul Ryan, R-Wisc., goes before the House Rules Committee for final work on his budget to fund the government in fiscal year 2015. (J. Scott Applewhite/AP)

A key chapter in the still-young career of Rep. Paul Ryan (R-Wis.) came to a close Thursday, as the House approved his final budget proposal, setting up several critical months in which he must decide his next political move.

With his term as House Budget Committee chairman expiring, Ryan, 44, must choose between running for president in 2016 or seeking to chair the Ways and Means Committee. The 2012 vice presidential nominee has kept his thinking private, making enough moves in each direction to keep even his close allies guessing about his plans.

“I honestly don’t think he knows,” said Rep. Sean Duffy (R-Wis.), who was elected in 2010 campaigning on Ryan’s budget proposals.

After winning approval of an austere budget outline — with its proposed $5 trillion in savings over 10 years and major overhaul of Medicare — Ryan left Washington over Congress’s two-week break to trek across the world, feeding the impression that he’s seriously considering a presidential bid.

His first stop will be Friday in Iowa, where he will be the keynote speaker at the state Republican Party’s Lincoln dinner in Cedar Rapids. It’s his second trip to the first-in-the-nation caucus state, and it shows Ryan is playing to both wings of the bitterly divided Iowa GOP.

In the fall, he headlined Gov. Terry Branstad’s birthday fundraiser, a crowd of 800 Republican establishment figures. Friday’s appearance will be before a clutch of conservatives and libertarians who took over the state’s Republican Party and are in a feud with Branstad’s organization. He will later join a congressional delegation traveling throughout Asia.

At the same time, most of Ryan’s political work is designed to benefit his House Republican colleagues. He has been quietly attending events across the country to raise money for their campaigns. Ryan’s advisers said he raised $1.7 million for candidates and $3.3 million for GOP committees.

Combined with the more than $500,000 he donated to candidates via his political action committee, Ryan has poured more than $5.5 million into Republican coffers since the start of 2013. That’s the sort of thing that draws the attention of his colleagues, who will vote for the next Ways and Means chairman.

Officially, Ryan has said that he is focused on 2014 and building an even larger GOP majority in the House and hoping the Senate will flip to GOP control. He has said he will decide on a presidential run in early 2015.

Some Ryan supporters say that his turn on the 2012 national ticket gave him such a prominence among GOP voters that he does not have to aggressively pursue early primary states the way some other potential candidates are. “There’s no need to make a decision in a hurry,” said Rep. Tom Cole (R-Okla.), a senior member of Ryan’s Budget Committee.

However, Cole is among the Ryan fans who think that by November or December, he must make clear whether he wants to run for president because Republicans want an active, aggressive chairman of the Ways and Means Committee.

“You can’t let us choose you for Ways and Means, and then be off running for president a few months later. I don’t think you can do both,” Cole said.

There is no official prohibition on being a chairman and running for president, but some consider the committee — with its jurisdiction over tax and entitlement policy — so important that they would want more than a caretaker atop the panel.

Some Ryan supporters say that he is certain to run for the committee gavel and will wait well into 2015 to see how the field develops; if no clear front-runner emerges, he could resign his chairmanship and be a late entrant into the presidential race.

Should Ryan forgo a presidential bid, his election as committee chairman is considered a lock by some because of the sheer devotion that many first and second-term lawmakers feel for him.

More so than House Speaker John A. Boehner (Ohio) or Majority Leader Eric Cantor (Va.), those younger Republicans view Ryan as the ideological soul of the GOP caucus. They campaigned on his budget proposals in 2010, then voted for them in 2011 and faced countless attack ads from Democrats in 2012 for backing Ryan.

“We’re forever tied together,” Duffy said.

Building a political operation is still somewhat new to Ryan, who won his first House race in his Janesville-based district in 1998 and largely coasted to reelection in every campaign thereafter. In the first quarter of this year, he brought in $1.4 million, his largest fundraising haul in any three-month period, raising money at a clip that would provide him a foundation for a presidential bid next year. He has more than $4 million in cash on hand.

Ryan is writing a book that is meant to be a policy tome, focusing on conservative ideas that can lift the poor into the middle class. As part of this effort, he visited a predominantly African American Baptist church in Indianapolis on Monday and saw a boot camp for troubled men and youths there.

“I’m trying to figure out how not to get in the way but help facilitate these stories so we have more of them throughout the country,” Ryan told the men.

Some question whether the congressman has enough fire in his belly to run an aggressive presidential campaign and whether he has the right political antenna. On his last Iowa trip, some GOP insiders approached Ryan’s team about putting together smaller events with power brokers whose support would be key to winning the state’s presidential caucus in 2016, according to Iowa GOP veterans.

Ryan turned down those offers. One Iowa Republican operative, who spoke on the condition of anonymity to discuss the matter freely, said that in the past month he had been raising money for another candidate and had not come across a single big donor who had been approached by Ryan’s team.

Some Iowa establishment figures question why he is attending Friday’s event, because the operatives currently aligned with the Iowa Republican Party are supporters of Ron Paul, a libertarian-leaning former congressman and father of Sen. Rand Paul (R-Ky.), the likely 2016 contender whom this crowd will drift toward supporting.

Even some of Ryan’s friends think the congressional brand of the Republican Party is so tainted by its fiscal battles with Obama that the GOP needs a governor to run as an outsider in 2016. Moments after Ryan finished speaking at Branstad’s Iowa event in November, the governor told reporters that he, too, wants a Republican governor, not Ryan, at the top of the ticket.

Yet some of those governors have stumbled of late, particularly Chris Christie of New Jersey. Others, such as Wisconsin Gov. Scott Walker, a friend of Ryan’s, have not quite impressed crowds at presidential cattle calls. If none of the governors catches on, some Ryan backers believe there eventually will be a “Draft Ryan” movement from establishment types.

As he closed down debate Thursday on his budget, Ryan delivered a brief speech that could be interpreted as a presidential stump speech — or an audition for how he would run the Ways and Means Committee. He talked about reshaping the health-care system, creating a “pro-growth” tax code and increasing domestic energy production.

“We have made our choice with this budget,” he said. “I trust the American people to make theirs.”

Now, the wait is on for Ryan to make his own choice.