US officials say Saudi crown prince has legal immunity in Khashoggi murder, a stark contrast to Biden's pledge to hold him to account

• The Biden administration said Mohammed bin Salman gets immunity in the killing of a journalist.
• It made the argument after Jamal Khashoggi's fiancée sued the Saudi crown prince in the US.

The Biden administration said that Saudi Arabia's crown prince should have legal immunity over the 2018 murder of Jamal Khashoggi, despite President Joe Biden's own pledges to hold him personally to account.

A Washington Post journalist and critic of the Saudi government, Khashoggi was lured into the Saudi consulate in Istanbul 2018. There, he was murdered and dismembered by agents the CIA says were working on Crown Prince Mohammed bin Salman's direct orders.

Biden pledged on the campaign trail to make the crown prince pay for the killing, and render his nation a "pariah."

In office, he said he has personally told Crown Prince Mohammed he believes him to be responsible, but has done little to hold him to account as the US seeks to maintain ties with Saudi Arabia, one of the world's biggest oil producers.

US officials made the argument about the prince's immunity in court papers filed Thursday, part of a civil lawsuit against Crown Prince Mohammed by Khashoggi's fiancée, Hatice Cengiz.

The Biden administration argued that since Crown Prince Mohammed was recently appointed as Saudi Arabia's prime minister, he has "sovereign immunity" from prosecution.

"The United States government has expressed grave concerns regarding Jamal Khashoggi's horrific killing and has raised these concerns publicly and with the most senior levels of the Saudi government," the Department of Justice said in its filing.

"However, the doctrine of head of state immunity is well established in customary international law," it argued.

Officials said that acknowledging this immunity "does not reflect a judgment on the underlying conduct at issue."

Biden's vow to take a tougher stance with the Saudis over the killing than his predecessor, Donald Trump, is one a number of issues that have roiled US-Saudi relations.

Biden walked back from his harsh rhetoric after taking office, and made a conciliatory visit to the crown prince over the summer. While there Biden said he confronted Crown Prince Mohammed over the murder, a claim Saudi officials later disputed.

The visit did little to mend relations overall, and the situation worsened in October when the Saudis decided to cut oil production in tandem with Russia.

In doing so, they are said to have thrown aside a secret deal with the Biden administration to do the exact opposite and increase production.

Analysts believe that Crown Prince Mohammed is engaging in a power play with Biden, seeking to form closer ties with US rivals Russia and China while offering some diplomatic concessions to the US in the knowledge that Washington is unlikely to significantly weaken its support.