Matt Brittin, Head of the company for EMEA, said: “We are sorry to anybody that's been affected.”
Marks&Spencer are amongst the firms pulling their adverts, saying: “In order to ensure brand safety, we are pausing activity across Google platforms whilst the matter is worked through."
Sky are also considering suspending their ads.
Sky, the owner of Sky News, said: "It is clearly unacceptable for ads to be appearing alongside inappropriate content and we are talking with Google to understand what they are doing to stop this."
Previously, Google's Jamie Gavin said: "Brands do have to take a bit of responsibility themselves."
However, Brittin said Google was looking at better defining hate speech and inflammatory content, simplifying controls available to advertisers.
He also added that Google was going to improve its efforts to remove “bad content” - albeit in the context of 400 hours of content being uploaded, on average, to YouTube every minute.
MPs have recently said that Google was profiting from hatred after it failed to remove videos from groups allegedly linked to terrorism.
It is understood that Google have previously appeared in front of senior civil servants and apologised about hosting extremist content, pledging a review of their advertising systems.
Yvette Cooper MP, Chair of the Home Affairs Select Committee, has said that Google's failure to remove hate videos was "frankly astonishing".
Mark Mulligan, a media and technology consultant at Midia, told the BBC that the complaints "were not new" and showed the internet was "still in its adolescence".
He said: "When the internet was founded, it was all about doing away with the gatekeeper. But now we're facing fake news and inappropriate content and that clashes with business models like Google's which are built on selling advertising."