"We've spent actually, I think, quite a lot more than than expected – probably on the order of hundreds of millions of dollars more," Musk said.

Known as Crew Dragon, the spacecraft would carry as many as seven people to the International Space Station and more. But, while much of the spacecraft's funding came from NASA's award of $2.6 billion in 2014, SpaceX founder and CEO Elon Musk noted in a briefing on Thursday that the company has also put a substantial sum of money itself to build and test the spacecraft.

LOS ANGELES — SpaceX is in the final stages of developing the capsule it will use to launch astronauts, a project that has commanded the company's resources and even finances over the last few years.

Musk spoke alongside NASA Administrator Jim Bridenstine at SpaceX's headquarters in Los Angeles on Thursday, as the pair provided an update on Crew Dragon. The NASA funding for the capsule has come under the Commercial Crew program, which is the agency's solution to once again launch U.S. astronauts from U.S. soil. Since the end of the Space Shuttle program in 2011, astronauts have flown to the International Space Station (ISS) aboard Russian Soyuz spacecraft.

While SpaceX has had to add funding to build Crew Dragon, according to Musk the company is now sticking closely to what it's been allotted.

"The SpaceX program is within 1% of the [NASA] budget; it's right on budget," Musk added.

Musk further explained SpaceX putting additional money into Crew Dragon, as well as part of what he believes has caused delays in the Commercial Crew program's progress.

"As Jim was was alluding to, the NASA request for Commercial Crew for several years was substantially reduced by Congress – I think, in some cases by 50%. So it's pretty hard to stay on schedule if you've got half as much money. But we didn't spend more money. It just took longer," Musk said.

Bridenstine agreed with Musk's point, saying Commercial Crew indeed did suffer setbacks from funding.

"It is absolutely true that there were certain years early, early on that set us back because we weren't adequately funded," Bridenstine said

"We're past that. We are now focused like a laser on the right things to achieve the end state that we both desire, which is American astronauts launching on American rockets," Bridenstine said.

Bridenstine further explained some of the behind-the-scenes for NASA's funding process and how taxpayer dollars are spent towards programs such as SpaceX's.

"It's based on milestone payments," Bridenstine said. "And of course, our contractors make proposals, and then we award based on those proposals. So all of that was agreed to up front."

"What we're trying to do is get back to a day where we have realistic costs and schedules," Bridenstine added. "In order to achieve the diplomatic goals and the strategic goals of our country – to have our international partners with us and a coalition of nations to go to the moon to stay – in order to achieve that we have to have credibility in our programs. And, right now, the one program that we need the most credibility in the fastest is the Commercial Crew program. And SpaceX is a big part of that."