The former Fox News host Tucker Carlson, declaring, “We’re back,” said on Tuesday that he was starting a new show on Twitter, a sign that negotiations to reach an amicable separation with the network, where he is still under contract, had broken down.
Mr. Carlson offered no details of when his new program would begin or what kind of content it would have — questions that highlight the uncertainties surrounding his departure from Fox News, which ultimately could block any attempt by the host to return to a prominent role in conservative media.
A representative for the Fox Corporation, which has been engaged in negotiations over the details of Mr. Carlson’s exit from the network since he was taken off the air last week, had no comment.
Mr. Carlson’s remarks, posted on Twitter, consisted of a three-minute monologue delivered directly to the camera. The post itself could violate the terms of his contract with Fox, which prevent Mr. Carlson from hosting a show on an alternate network.