The two companies filed suits in a federal court in June, arguing a right to disclose more information about user data requests made by the government under the controversial Foreign Intelligence Surveillance Act.
Their representatives met six times with US officials and agreed to extend the deadlines for the government to reply to the lawsuits, allowing time for negotiations that ended in failure, Microsoft general counsel Brad Smith said.
"We hoped that these discussions would lead to an agreement acceptable to all. While we appreciate the good faith and earnest efforts by the capable government lawyers with whom we negotiated, we are disappointed that these negotiations ended in failure," Smith said in a blog post.
"To followers of technology issues, there are many days when Microsoft and Google stand apart," Smith said.
"But today our two companies stand together...We believe we have a clear right under the US Constitution to share more information with the public."
The issue became highlighted after Edward Snowden, a former IT contractor at the National Security Agency (NSA), disclosed that the US authorities were tapping into Internet user data, sometimes using national security letters that bar companies from telling anyone about the requests.
The public deserves and the Constitution guarantees more than this first step, he added.