Google has said it is introducing new tools after some companies withdrew ads because they appeared alongside extremist content.
The company's chief business officer said it was taking a tougher stance on hateful, offensive and derogatory content.
He said he knew advertisers did not want their ads "next to content that doesn't align with their values".
The firm is hiring more staff and overhauling policies.
Google's Matt Brittin told a conference earlier yesterday that "I want to start by saying sorry" and that the company must "take responsibility" over the issue which saw tax-payer funded UK-government adverts appear alongside extremist material on YouTube.
Chair of the UK's Home Affairs Select Committee Yvette Cooper said in response that Google still has questions to answer over the incident.
"They are right to apologise for failing to stop extremists making profits from hatred, and for making profits themselves from advertising on these videos," she said.