A US House intelligence panel will investigate US President Donald Trump’s response to the murder of Washington Post journalist Jamal Khashoggi as part of a “deep dive” next year into US-Saudi Arabia connections.

US Representative Adam Schiff, the committee’s top Democrat, told the Post on Saturday (Friday local time) they will investigate the US intelligence assessment of Khashoggi’s death as well as the war in Yemen, the stability of the Saudi royal family and the kingdom’s treatment of critics and the press.

The probe comes as Mr Trump rebuked his own intelligence agency’s conclusion that Saudi Prince Mohammed bin Salman, “with high confidence”, ordered the killing of Khashoggi at the Saudi consulate in Istanbul on October 2.

He told reporters at his Mar-a-Lago resort during Thanksgiving celebrations the CIA simply “had feelings” on the matter before suggesting “the world” should be held responsible for Khashoggi’s death because it is a “vicious place”.

He said the CIA “did not come to a conclusion … they have feelings certain ways” while the crown prince “denies it vehemently”.

The president then doubled-down on his comments, suggesting an oil deal with Saudi Arabia was far more important than holding anyone accountable for Khashoggi’s murder.

Mr Schiff is in line to become committee chairman next month when his party takes control of the US House of Representatives following gains in November’s congressional elections.

That will allow Democrats to exercise oversight of Mr Trump and his administration, giving them investigative power, including the ability to issue subpoenas and hold hearings.

The White House did not respond to a request for comment.

Mr Trump has repeatedly stressed the importance of the United States’ relationship with Saudi Arabia following Khashoggi’s death, calling the kingdom a “steadfast partner” that has agreed to invest “a record amount of money” in the US.

“Certainly we will be delving further into the murder of Khashoggi,” Mr Schiff told the Post.

“We will certainly want to examine what the intelligence community knows about the murder.”

Khashoggi was for decades close to the Saudi royal family as an advisor, but he fell out of favour with the family and sought exile in the United States where he wrote regular opinion pieces for The Washington Post criticising the policies of the crown prince.

Mr Schiff said his panel will examine the CIA’s findings as well as whether Mr Trump’s private financial relationship with the Saudis influenced his response as president.

“There are a whole set of potential financial conflicts of interest and emoluments problems that Congress will need to get to the bottom of,” Mr Schiff said.

“If foreign investment in the Trump businesses is guiding US policy in a way that’s antithetical to the country’s interests, we need to find out.”

Mr Trump, who still owns his business as president but has said he relinquished day-to-day control, told a rally in 2015 he earned “hundreds of millions” of dollars from Saudi purchases.

Mr Trump has defended his stance toward Saudi Arabia, a key US ally in the Middle East, citing US arms deals with Riyadh and the larger US strategy toward Iran.

-with AAP