WASHINGTON — The Central Intelligence Agency has concluded that the Saudi crown prince, Mohammed bin Salman, ordered the killing of the journalist Jamal Khashoggi, according to American officials.
The C.I.A. made the assessment based on the crown prince’s control of Saudi Arabia, which is such that the killing would not have taken place without his approval, and has buttressed its conclusion with two sets of crucial communications: intercepts of the crown prince’s calls in the days before the killing, and calls by the kill team to a senior aide to the crown prince.
The C.I.A. has believed for weeks that Prince Mohammed was culpable in Mr. Khashoggi’s killing but had been hesitant to definitively conclude that he directly ordered it. The agency has passed that assessment on to lawmakers and Trump administration officials.
The change in C.I.A. thinking came as new information emerged, officials said. The evidence included an intercept showing a member of the kill team calling an aide to Prince Mohammed and saying “tell your boss” that the mission was accomplished. Officials cautioned, however, that the new information is not direct evidence linking Prince Mohammed to the assassination, which was carried out in the Saudi Consulate in Istanbul.
The intercepts do show that Prince Mohammed was trying to find ways to lure Mr. Khashoggi back to Saudi Arabia, although the crown prince did not specifically say in the phone calls that he wanted to have Mr. Khashoggi killed, according to people briefed on the intelligence findings.
One former official said intelligence agencies were also examining communications between Mr. Khashoggi and the Saudi ambassador to Washington, Prince Khalid bin Salman, the brother of the crown prince.
Prince Khalid’s denial was unusually swift. In a Twitter post on Friday, he said that “the last contact” he had with Mr. Khashoggi was by text on Oct. 26, 2017, and that he never suggested that Mr. Khashoggi go to Turkey.
“I never talked to him by phone and certainly never suggested he go to Turkey for any reason,” he tweeted.
The C.I.A.’s assessment was first reported Friday by The Washington Post. A C.I.A. spokesman declined to comment.
The increasingly definitive assessment from the spy agency creates a problem for President Trump, who has tied his administration to Prince Mohammed and proclaimed him the future of Saudi Arabia, a longtime American ally.
But the new assessment by the C.I.A. is sure to harden the resolve of lawmakers on Capitol Hill to continue to investigate the killing of Mr. Khashoggi and punish Saudi Arabia.
Jared Kushner, the president’s son-in-law and senior adviser, has been particularly close to Prince Mohammed. Mr. Kushner has long advocated that a strong relationship with the Saudis is in the United States’ interest, and he has pushed to maintain support for the crown prince despite the death of Mr. Khashoggi, who Saudi officials now say was killed with a lethal dose of tranquilizers and dismembered. Previously, Saudi officials said that Mr. Khashoggi had been strangled.
Neither administration officials nor intelligence officers believe the controversy over Mr. Khashoggi will drive Prince Mohammed from power, which is one reason White House officials believe cutting ties with the prince would not be in the interest of the United States.
“It is one of those acts that must cause us to re-examine the relationship and how much dependence we place on it,” said Representative Adam B. Schiff, Democrat of California, who is set to lead the House Intelligence Committee next year.
Senate Republicans, according to people briefed on their deliberations, want to see more decisive steps from Saudi Arabia to try to defuse the crisis. One move that could blunt tougher congressional action, they said, would be for Riyadh to release some dissidents, including the leaders of the effort to allow Saudi women to drive.
Lawmakers are hoping to use the controversy over the assassination to try to force an end to the Saudi war in Yemen, or at least the American military support for it.
The United States has already announced that it would end air-refueling flights for the Saudi Air Force over Yemen, and it has sanctioned 17 Saudis for their alleged involvement in the killing of Mr. Khashoggi.
Mr. Schiff said the Trump administration’s move to cut off refueling for Saudi planes conducting airstrikes is more significant than the sanctions.
“If we truly want to affect Saudi behavior, it is going to be more important to focus on bringing an end to the campaign in Yemen than these announcements of sanctions on these individuals we are unlikely to be able to reach,” he said.
Mr. Schiff said he was pushing for a classified briefing for the entire House on the war in Yemen and American support for the Saudi campaign. Congressional Republicans have also said they would support such a briefing.
Skepticism in Congress about the Saudis has grown as Saudi officials have given multiple and conflicting accounts of what happened in the consulate in Istanbul. This week, they announced they would seek the death penalty against some of the perpetrators.
C.I.A. officials have long been unsure about Prince Mohammed and his abilities to lead the kingdom. The agency, and its former director, John O. Brennan, had a close relationship with Prince Mohammed’s rival, Mohammed bin Nayef. The young crown prince outmaneuvered his rival in 2017 to consolidate his position.
Turkish officials made tape recordings of the killing of Mr. Khashoggi in the consulate, and the Turkish government was the first to say that it had definitive proof that Mr. Khashoggi was assassinated.
But Turkish official have stopped short of saying there is definitive evidence of Prince Mohammed’s role in the death on the recordings they have.
An earlier version of this article misstated when Prince Khalid bin Salman last communicated with Jamal Khashoggi. It was in October 2017, not this October.
Eric Schmitt and Mark Mazzetti contributed reporting.