Donald Trump said Thursday that he plans to outsource key aspects of his presidential campaign to the Republican National Committee.

Trump's shoestring operation was good enough to win a primary, succeeding on his ability overwhelm opponents by dominating the new cycle. But Trump Tower is woefully unprepared to take on Hillary Clinton, lacking any semblance of a sophisticated field or digital program.

The RNC has spent the last three years building, from scratch, a modern voter turnout that was always intended to serve as the foundation for the eventual 2016 nominee's campaign infrastructure. That includes 287 paid staff in 11 battleground states, plus another 179 set to joint them.

But the assumption was always that the presidential nominee would bring something the table in the way of field and data analytics, built during the primary contest, as is typical of Republican standard bearers. Trump isn't the typical candidate, and is instead handing off responsibility for voter turnout to the RNC.

The move is making some Republicans nervous. They fear the committee will be too consumed with Trump to focus on House, Senate and governors races.

"There are worries," said GOP strategist Kevin Madden, a veteran of Mitt Romney's 2012 campaign, "since Trump never really built much of an operation."

Given that, some Republican operatives are saying that Trump to delegate was the only choice available to him. "It's the only logical thing for him to do," a veteran GOP campaign strategist said.

Trump is expressing confidence in RNC Chairman Reince Priebus' ability to manage all the party's needs — his and those down ticket.

"As far as building the infrastructure of the campaign, the RNC has been doing it for many years. Reince has really upped it and all over the country they have very good people," Trump told reporters during a news conference while campaigning in North Dakota.

"Part of the benefit is we get to use those people," he continued. "And while I'm raising a lot of money for them, and they're going to use that not only for me, they're going to use that also for other people running for office."

A few hours later, perhaps anticipating questions about the RNC's readiness, Chris Carr, the committee's political director, issued a memorandum to the press detailing the committee's voter turnout programs and plans for immediate expansion.

The message the RNC is trying to hammer home is that Clinton's more robust campaign operation is less an advantage than it appears because Trump gets to use a field operation that has had paid staff in crucial electoral battlegrounds since a few months after the 2012 presidential election.

RNC spokeswoman Lindsay Walters dismissed concerns that the committee is taking on too much to serve down ticket candidates — and that the Trump campaign's lack of an infrastructure could hobble the nominee in November.

"Under Chairman Priebus we have built the largest and earliest ground game in political history," Walters said.

Compounding the anxiety of some Republicans are jitters about resources.

Most Republican nominees enter the general election having cultivated and assembled a loyal fundraising network that they can mine for quick cash as they expand party operations for the fall. Trump doesn't have one.

The New York businessman, a wealthy real estate magnate, funded most of his campaign via loans from his personal fortune, with some money coming in from small donors. By leveraging his celebrity to hold mass rallies and attract constant news coverage, Trump was able to get away with spending little on advertising and get-out-the-vote activities like field and data.

But Trump is not willing to self-fund the more expensive general election battle. He recently signed an agreement with the RNC to bring in money from wealthy donors who can write checks for as much as $449,000, while giving his approval for super PACs to pick up the rest of the slack.

The problem is that fundraising networks don't bring in hundreds of millions of dollars overnight. Romney, among the most prolific fundraisers in GOP history, spent years cultivating his donor network, so that by this time in the primary cycle it was well positioned.

The RNC has had a very successful election cycle fundraising, bringing in $144.8 million thus far, with $17.4 million in the bank as of April 30.

But the demands of running a presidential campaign, as charged to do by Trump, are going to require considerably more money, and fast. Republicans in down-ticket races wonder if there is going to be any cash left over to help them.

"We're a little worried, but it's not panic time, yet," said a GOP operative working for down-ticket candidates.

Gabby Morrongiello contributed to this report.