Google and Facebook on Monday announced measures aimed at stopping the spread of "fake news" on the internet by threatening to ban web publishers from ad networks. Google said it is working on a policy change to prevent websites that misrepresent content from using its AdSense advertising network, while Facebook updated its advertising policies to spell out that its ban on deceptive and misleading content applies to fake news.

The shifts comes as Google, Facebook and Twitter face a backlash over the role they played in the U.S. presidential election by allowing the spread of false and often malicious information that might have swayed voters toward Republican candidate Donald Trump.

Facebook Chief Executive Mark Zuckerberg has responded saying that the site had no role in influencing the election.

"We do not integrate or display ads in apps or sites containing content that is illegal, misleading or deceptive, which includes fake news," Facebook said in a statement, adding that it will continue to vet publishers to ensure compliance.

Google's move similarly does not address the issue of fake news or hoaxes appearing in Google search results.

The change is aimed at assuring that publishers on the network are legitimate and eliminating financial incentives that appear to have driven the production of much fake news.

"Moving forward, we will restrict ad serving on pages that misrepresent, misstate, or conceal information about the publisher, the publisher's content, or the primary purpose of the web property," Google said in a statement.

Google did not detail how it would implement or enforce the new policy.

Google has long had rules for its AdSense program, barring ads from appearing next to pornography or violent content. The company uses a combination of humans and artificial intelligence to review sites that apply to be a part of AdSense.