The internet giant sent a letter to lawmakers and posted comments on its public policy blog defending the changes to take effect March 1, which will consolidate the policies of its offerings such as search, mail, video and map usage.
"Protecting people's privacy is something we think about all day across the company, and we welcome discussions about our approach," Google public policy chief Pablo Chavez said in the blog post.
Some privacy advocates have expressed concern that users will not be able to "opt out" of the new policy, which will allow advertisers to develop personalised messages based on web searches, use of Android mobile devices or activity on other Google products.
But Chavez said that "some important things aren't changing: We're still keeping your private information private - we're not changing the visibility of any information you have stored with Google."
Additionally, "We're still allowing you to do searches, watch videos on YouTube, get driving directions on Google Maps, and perform other tasks without signing into a Google Account."
He added that Google will continue to offer "privacy tools" including an ad preference manager, and "We still won't sell your personal information to advertisers."
For users who dislike the policy, he noted, "We're still offering data liberation if you'd prefer to close your Google Account and take your data elsewhere."
The change comes nearly a year after Google reached a settlement with the US Federal Trade Commission over privacy concerns with Google Buzz, a social networking tool. The deal called for audits of Google's privacy efforts.
US Representatives Edward Markey and Joe Barton sent a letter to the FTC last week asking if the planned changes are a violation of the settlement.
"This new policy and omission of a consumer opt-out option on a product-by-product basis raises a number of important privacy concerns," the two lawmakers said in their letter.
Google said in its letter to lawmakers that "our approach to privacy has not changed," and that Google users "continue to have choice and control" over private data by not signing into accounts or by using other tools like anonymous search or chat.