US President Donald Trump says imposing sanctions against Saudi Arabia is a possibility if the kingdom is found guilty in the suspected murder of dissident Saudi journalist Jamal Khashoggi.

Speaking to reporters on Friday, Trump said he would work with Congress to come up with the best response when it becomes clear what happened to Khashoggi, who was last seen entering the Saudi consulate in the Turkish city of Istanbul on October 2.

"Could be, could be,” Trump said when asked about sanctions. “We are going to find out who knew what, when and where and we'll figure it out.”

"I will very much listen to what Congress has to say. They feel very strongly about it also. So I'll be doing this with Congress," he added.

Many lawmakers on both sides of the US political spectrum have called on Trump to pressure Riyadh until it comes clean.

Turkish and American intelligence reports confirm that Khashoggi was indeed murdered at the Saudi mission by direct order of Saudi Crown Prince Mohammed bin Salman.

Trump, however, has taken a cautious line, pledging to punish the perpetrators without risking strong financial ties with Riyadh.

He has specifically pointed to his $110 billion military deal with the kingdom, warning that harsh reactions would alienate Riyadh and push it towards Russia.

"Saudi Arabia has been a great ally of ours. That's why this is so sad," he said Friday.

“They've been a tremendous investor in the United States. They've invested and the jobs are incredible,” he added.

In an interview with The New York Times in the White House on Thursday, Trump stopped short of saying bin Salman ordered the murder, but acknowledged that the allegations of Saudi involvement in the atrocity had created a serious foreign policy crisis for his presidency.

Khashoggi, a US green card holder and a columnist for The Washington Post, used to have close ties with bin Slaman before losing his favor and turning into a firm critic of his policies.