Germany will bar 18 Saudis from entering its territory and Europe's Schengen passport-free zone over the country's alleged links to the murder of Jamal Khashoggi, Foreign Minister Heiko Maas said today.

Berlin has "decided that Germany should impose an entry ban on 18 Saudi citizens, who are presumed to be in connection with this deed, in the Schengen information system," Mr Maas told reporters.

Journalist Jamal Khashoggi was killed inside the Saudi embassy in Istanbul in early October. Turkey has given the US government a recording of the murder, but US President Donald Trump said he would not listen to it "because it's a suffering tape, it's a terrible tape."

Mr Trump said he does not want to listen to it, despite facing mounting pressure to punish Saudi Arabia for the killing.

"I don't want to hear the tape, no reason for me to hear the tape," he said in an interview on Fox News.

"I know everything that went on in the tape without having to hear it ... It was very violent, very vicious and terrible."

Mr Trump also said he wants to maintain a close alliance with Saudi Arabia despite Mr Khashoggi's death, and questioned the alleged role of Saudi Crown Prince Mohammed bin Salman, who is known as MbS and is the kingdom's de facto ruler.

"He told me that he had nothing to do with it," Mr Trump said, adding that "many people" also said the crown prince had no knowledge of the killing.

The interview was taped on Friday, hours before government sources said the Central Intelligence Agency (CIA) had briefed the Trump administration on the murder and its belief that MbS ordered it.

Mr Trump said on Saturday that the CIA assessment was "very premature" and in the interview that aired on Sunday he said it may never be possible to know who ordered Jamal Khashoggi's murder.

The president faces intense pressure from senior Democratic and Republican lawmakers to take tougher action against Saudi Arabia. Some have said he should suspend arms sales to the kingdom and drop his support for MbS, but Mr Trump has so far resisted that pressure.

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.

Saudi Arabia is a major oil supplier and a close ally of the United States in countering Iranian power in the Middle East.

Republican Senator Lindsey Graham, a close ally of Trump, said on Sunday he had no doubt about MbS' involvement in ordering the murder of Khashoggi.

"They are an important ally but when it comes to the crown prince, he's irrational, he's unhinged and I think he's done a lot of damage to the relationship (between) the United States and Saudi Arabia. And I have no intention of working with him ever again," he said on NBC's Meet the Press.

In his first public remarks since the Khashoggi murder, Saudi King Salman (father of MbS) today heaped praise on the kingdom's judiciary.

The public prosecutor in the country last week exonerated MbS of involvement in the murder, contrary to the CIA's conclusion that he ordered the assassination.

The Saudi prosecutor called for the death penalty against five men as it announced indictments against 11 people and said a total of 21 individuals were in custody in connection with the killing.

"The kingdom was founded on Islamic principles of justice and equality, and we are proud of the efforts of the judiciary and the public prosecution and the performance of the job entrusted to them," the king said in his annual address to the Shura Council, a top advisory body.

The 82-year-old monarch did not directly address the murder of The Washington Post columnist in his speech.

Saudi Arabia - which quickly dismissed the reported CIA findings - has offered shifting accounts of what happened, initially saying Khashoggi left the embassy after receiving his documents and later that he was killed when an argument degenerated into a fistfight.

In the latest version, the Saudi prosecutor said a 15-member team went to Istanbul to bring Khashoggi back to the kingdom "by means of persuasion", but killed him instead in a rogue operation.