The administration on Thursday imposed economic sanctions on 17 Saudi officials for their alleged role in the killing, but they did not target the Saudi government.
"It's a suffering tape".
It's unusual, however, because while the interview with Fox was filmed on Friday, Trump told reporters outside the White House on Saturday morning, just before leaving for a trip to visit fire damage in California, "we haven't been briefed yet" about the Khashoggi murder.
Khashoggi, a journalist for WaPo, was brutally killed after he entered a Saudi consulate in Turkey on October 2.
Jamal Khashoggi, a columnist for The Washington Post and a critic of the Saudi government, was slain on Oct 2 inside the Saudi consulate in Istanbul while collecting paperwork for his upcoming wedding.
South Carolina Republican Senator Lindsey Graham, who is in line to be the next chairman of the Senate Judiciary Committee, has been one of the most vocal U.S. lawmakers to call for action against those found responsible over Khashoggi's murder and to criticise Saudi Arabia over its constantly shifting narrative.
When Wallace asked him his reason, Trump replied: "Because it's a suffering tape, it's a bad tape".
"We're going to come up with a report as to what we think the overall impact was and who caused it, and who did it", he said.
Earlier this week, Washington sanctioned 17 Saudi officials, some close to the Crown Prince, over Khashoggi's death, freezing their assets in the United States and refusing them entry to the country.
CIA Director Gina Haspel and Secretary of State Mike Pompeo briefed Trump about the prince's connection to Khashoggi's murder aboard Air Force One on Saturday as the president headed to California to meet with officials about the wildfires.
After the killing, one of the team members was was heard, on recording by a listening device planted in the consulate by the Turks, telling a close adviser to the crown prince, Saudi al-Qahtani, "tell your boss" it's done. And really the only thing they understand over there is strength. "But I can say this, he's got many people now that say he had no knowledge".
The State Department said the USA government "is determined to hold all those responsible for the killing. accountable" but that "numerous unanswered questions" remain.
Trump added, "He told me that he had nothing to do with it".
The senior United States official told CNN on Friday the conclusion is based on a recording provided by the Turkish government and other evidence, including American intelligence.
"I never talked to him by phone and certainly never suggested he go to Turkey for any reason".
The Saudi authorities said that Khashoggi died in a "brawl" in its consulate. A US government official told Fox News on Saturday that no final assessment or conclusion relating to the crown prince's involvement had been reached, nor had a so-called "smoking gun" been found.