A Chinese Foreign Ministry spokesman pushed back on Wednesday against assertions by Lt. Gen. Michael T. Flynn, who is President-elect Donald J. Trump’s choice for national security adviser, that China was allied with “radical Islamists.”

The spokesman, Lu Kang, was asked at a regularly scheduled news conference in Beijing about Mr. Flynn’s accusations, which were made in a book released in July that he wrote with a co-author, “The Field of Fight: How We Can Win the Global War Against Radical Islam and Its Allies.”

“I hope everyone who takes a responsible attitude and is devoted to safeguarding China-U.S. relations and boosting China-U.S. cooperation can base their opinions on facts when taking a position,” Mr. Lu said. “Only in this way can mutual trust be enhanced.”

Mr. Flynn has said the United States must lead a global campaign against “radical Islam.” He has on occasion pushed conspiracy theories. For example, after the attack on the American diplomatic compound in Benghazi, Libya, in 2012, he kept asking intelligence officers working under him at the Defense Intelligence Agency in the Pentagon to look for involvement by Iran in the assault. There was no evidence of any ties to Iran.