A US intelligence report has implicated Saudi Crown Prince Mohammed bin Salman in the murder of exiled journalist Jamal Khashoggi in 2018.

The declassified report released by the Biden administration says the prince approved a plan to either capture or kill the US-based Saudi exile.

It is the first time America has publicly named the crown prince, who denies ordering the death.

Khashoggi was murdered while visiting the Saudi consulate in Istanbul.

He had been known for his criticism of the Saudi authorities.

As far back as 2018, the CIA reportedly believed that the crown prince had ordered the murder but the allegation that he was involved has never been made publicly by US officials until now.

US President Joe Biden is expected to take a firmer line than his predecessor Donald Trump on human rights and the rule of law in Saudi Arabia, a key American ally in the Middle East.

In a phone call on Thursday with the crown prince's father, King Salman, the president "affirmed the importance the United States places on universal human rights and the rule of law", the White House said.

According to sources quoted by Reuters news agency, the Biden administration is considering the cancellation of arms deals with Saudi Arabia that pose human rights concerns as well as the limiting of future military sales to "defensive" weapons.

Saudi authorities blamed his death on a "rogue operation" by a team of agents sent to return him to the kingdom, and a Saudi court tried and sentenced five individuals to 20 years in prison last September, after initially sentencing them to death.

In 2019, UN special rapporteur Agnes Callamard accused the Saudi state of the "deliberate, premeditated execution" of Khashoggi and dismissed the Saudi trial as an "antithesis of justice".

How was Khashoggi killed?

The 59-year-old journalist went to the consulate in October 2018 in order to obtain papers allowing him to marry his Turkish fiancée.

He had allegedly received assurances from the crown prince's brother, Prince Khalid bin Salman, who was ambassador to the US at the time, that it would be safe to visit the consulate. Prince Khalid has denied any communication with the journalist.

According to Saudi prosecutors, Khashoggi was forcibly restrained after a struggle and injected with a large amount of a drug, resulting in an overdose that led to his death. His body was then dismembered and handed over to a local "collaborator" outside the consulate, prosecutors said. The remains were never found.

Details were revealed in transcripts of purported audio recordings of the killing obtained by Turkish intelligence.

Khashoggi had once been an adviser to the Saudi government and close to the royal family but he fell out of favour and went into self-imposed exile in the US in 2017.

From there, he wrote a monthly column in the Washington Post in which he criticised the policies of Prince Mohammed.