“It is necessary for the media to restore people’s trust in the party, especially as the economy has entered a new normal and suggestions that it is declining and dragging down the global economy have emerged,” the essay said.

“The nation’s media outlets are essential to political stability, and the leadership cannot afford to wait for them to catch up with the times,” it said.

Mr. Xi’s directives would also make it harder for foreign governments to determine which Chinese journalists operating in their countries are legitimate news gatherers and which ones are agents serving propaganda, intelligence or other official interests. The major party and state-run news organizations have been greatly expanding their operations overseas, including in the United States.

Mr. Xi’s new policy came about because “despite the continuing tightening of control of the media over the last three years, Xi is not fully assured that the state media, even the most central ones such as Xinhua and CCTV, are fully under his control,” said Xiao Qiang, a scholar in Berkeley, Calif., who researches the party’s information control.

David Bandurski, the editor of the China Media Project at the University of Hong Kong, said that “under Xi Jinping, the centrality of the party is explicit for every single medium.”

“I think the sense is, ‘We own you, we run you, we tell you how things work,’ ” he said. “ ‘The party is the center, and you serve our agenda.’ This is much more central now, and it’s being defined for all media platforms, from social media to commercial media.”