If you've got an Amazon Fire TV, say goodbye to using it to watch YouTube.

The Google-owned video service is cutting access to the Amazon device on Jan. 1, a Google spokeswoman said on Tuesday. YouTube is also cutting access Tuesday for a second time to Amazon's Echo Show video device.

The moves signal that the ongoing battle between the world's biggest search engine and the world's largest online retailer may get messier in 2018.

"We've been trying to reach agreement with Amazon to give consumers access to each other's products and services," the Google spokeswoman said in a statement. "But Amazon doesn't carry Google products like Chromecast and Google Home, doesn't make Prime Video available for Google Cast users, and last month stopped selling some of Nest's latest products.

"Given this lack of reciprocity," she said. "We are no longer supporting YouTube on Echo Show and FireTV. We hope we can reach an agreement to resolve these issues soon."

Google and Amazon have been in an intensifying competition on multiple fronts, with Amazon pushing deeper into Google's turf of online advertising and Google moving into Amazon's territory of e-commerce and smart speakers. This competition over the years has spilled out into public view and often resulted in fewer options for customers. Still, it's unclear whether Google's latest move should be seen as a negotiating tactic by the search giant or a sign of more fighting between the two companies.

In one of the most recent spats between the two tech powerhouses, YouTube vanished from Amazon's Echo Show device in September, with Google saying Amazon's implementation of YouTube on the Echo Show violated its terms of service. The Show, unveiled in May, is essentially an Amazon Echo smart speaker with a built-in touchscreen display. YouTube returned to the Show last month, just in time for Black Friday, by directing users to YouTube's website, but Google is cutting access again.

"Echo Show and Fire TV now display a standard web view of YouTube.com and point customers directly to YouTube's existing website," an Amazon spokeswoman said. "Google is setting a disappointing precedent by selectively blocking customer access to an open website. We hope to resolve this with Google as soon as possible."