Amazon and Google have clashed publicly after access to YouTube was pulled from one of the online retailer's devices.
On Tuesday, YouTube stopped working on Amazon's Echo Show, a voice-controlled assistant with a screen that can display information and videos.
Both companies issued statements criticising one another. Amazon said Google had blocked YouTube on Echo Show "without explanation".
Google said the Echo Show delivered a "broken user experience".
While the Echo Show could play videos from YouTube, it did not provide all of YouTube's functions such as the ability to subscribe to channels or serve up video recommendations.
Google said in a statement: "Amazon's implementation of YouTube on the Echo Show violates our terms of service, creating a broken user experience. We hope to be able to reach an agreement and resolve these issues soon.
"We've been in negotiations with Amazon for a long time, working towards an agreement that provides great experiences for customers on both platforms."