U.S. Defense Secretary Jim Mattis said Saturday the "murder of Jamal Khashoggi in a diplomatic facility must concern us all."
"Failure of any nation to adhere to international norms and the rule of law undermines regional stability at a time when it is needed most," Mattis said in prepared remarks for the annual Manama Dialogue security conference in Bahrain.
The defense secretary said Secretary of State Mike Pompeo has already revoked some Saudi visas and "will be taking additional measures" against the responsible people.
A U.S. news report, meanwhile, says Salah bin Jamal Khashoggi, son of the journalist slain in Saudi Arabia's consulate in Istanbul, has arrived in the United States.
The dual U.S.-Saudi citizen had been banned from traveling by the Saudi government until earlier this week. The restriction on his passport was lifted following a photographed handshake with the Saudi Crown Prince and King Salman on Tuesday. News network CNN reported Friday that he has arrived, although his location was not clear.
The State Department said Secretary of State Pompeo was "pleased" at the lifting of the travel restriction. Pompeo had urged the Saudis to allow Salah Khashoggi to leave the country.
Saudi Foreign Minister Adel al-Jubeir said Saturday that the media coverage about the Khashoggi case has become "hysterical." He acknowledged that Saudi Arabia had made some mistakes, but promised the country will conduct a transparent probe into the killing.
Meanwhile, Turkish state-run news says Turkey has asked for extradition of the 18 men arrested in Saudi Arabia in connection with the killing.
Saudi Arabian Foreign Minister Adel al-Jubeir, however, dashed that hope Saturday when he said, "On the issue of extradition, the individuals are Saudi nationals. They are detained in Saudi Arabia and the investigation is in Saudi Arabia, and they will be prosecuted in Saudi Arabia."
Turkish President Recep Tayyip Erdogan urged Saudi Arabia Friday to disclose the location of Khashoggi's body and the identity of the "local cooperator" who allegedly disposed of the body after Khashoggi was killed in the Saudi consulate.
Speaking to provincial members of his AK Party in parliament, Erdogan said Ankara has more evidence related to the journalist's murder, but he did not give any details. He also said Saudi Arabia's chief prosecutor will visit Istanbul Sunday and will meet with Turkish officials as part of the investigation into Khashoggi's murder.
And Khashoggi's Turkish fiancee, Hatice Cengiz, told Turkish broadcaster Haberturk that although her fiance had been worried about visiting the consulate in Istanbul, he did not think he would be arrested or harmed in Turkey.
"He thought Turkey is a safe country and if he would be held or interrogated, this issue would be swiftly solved," Cengiz said.
She called on those responsible for his murder to be brought to justice.
Saudi Arabia acknowledged in a statement Thursday that Khashoggi's killing appeared to have been premeditated, on the basis of evidence supplied by Turkey.
What was left unclear was who premeditated the killing. The Saudi statement said, "The public prosecution continues its investigation with suspects ... to complete the course of justice." The Saudis fired five officials linked to the killing and have arrested 18 suspects.
International critics, including U.S. President Donald Trump, have said that the country's de facto ruler, Crown Prince Mohammed bin Salman, bears ultimate responsibility for the killing.
The Kremlin said Friday Russia believes the Saudi royals were not involved in the journalist's murder. Kremlin spokesman Dmitry Peskov said, "There's an official statement from the king, there's an official statement from the Crown Prince (Mohammed bin Salman) and no one should have any grounds not to believe them."
Saudi Foreign Minister Jubeir said ties between his country and the U.S. have remained "ironclad" and praised the foreign policy of the Trump administration as "rational, realistic."