Sundar Pichai, CEO of Google, speaks to the media before the opening of the Berlin representation of Google Germany in Berlin on January 22, 2019.

Google CEO Sundar Pichai says YouTube is too big to completely fix the site's problems with harmful content.

YouTube, which is owned by Google, has come under fire in the last couple of years, as content ranging from deniers of the Sandy Hook massacre to supremacist content has continued to show up on the site despite the company's attempts to filter it out.

During a CNN interview that aired Sunday, Pichai was asked whether there will ever be enough humans to filter through and remove such content.

"We've gotten much better at using a combination of machines and humans," Pichai said. "So it's one of those things, let's say we're getting it right 99% of the time, you'll still be able to find examples. Our goal is to take that to a very, very small percentage well below 1%."

Pichai said Google probably can't get that to 100%.

"Any large scale systems, it's tough," Pichai said. "Think about credit card systems, there's some fraud in that. ... Anything when you run at that scale, you have to think about percentages."

But Pichai added that he's "confident we can make significant progress" and that "enforcement will get better." He also said Google wishes it had addressed the problems sooner, since many of the videos have been running for years

"There's an acknowledgement we didn't get it right," he said. "We're aware of some of the pitfalls here and have changed the priorities."

Watch the video on CNN.