“Egypt is undergoing an existential battle,” he said, adding, “We must know the dimensions of the big conspiracy against us” that aims “to bring down this state.” And he warned of more hardship to come.

“There is struggle, pain and blood,” he said, recounting the hundreds of soldiers and police officers who have been killed in militant attacks. “Sinai’s battle is ongoing, it will not end in a few weeks or couple of months. Please, let us stand steadfast, and let no one break the will of the Egyptian people, or the army.”

Over the last few days, Egypt’s state institutions and the government’s loyalists have banded together, condemning terrorism but also moving against any kind of dissent against the government.

On Saturday, the owner of a major private satellite network replaced a talk-show host, Mahmoud Saad, who had been mildly critical of the government. In a statement, Al Nahar Television did not refer to a specific incident, but said that “freedom of expression cannot ever justify ridicule of the Egyptian Army’s morale.”

Other television programs known for showing opposing views in the past three years or more have quietly gone off the air. The private Egyptian news media has spoken in virtually unanimous support of the current government since Mr. Sisi, then a general, ousted President Mohamed Morsi of the Muslim Brotherhood last year. The statements by Al Nahar and the newspaper editors appeared to formalize the private news media’s policies of support for the government.