Trump has repeatedly said that he opposes any effort to jeopardize more than $100 billion in USA arms sales to Saudi Arabia, but that he would consider sanctions on the kingdom. He changed his tone once again late this week, raising the prospect of sanctions against Riyadh.
"The kingdom and all involved in this brutal murder must be held accountable, and if the Trump Administration will not take the lead, Congress must", he said.
On Saturday, U.S. President Donald Trump joined European leaders in pushing Saudi Arabia for more answers after Riyadh changed its story and acknowledged that the journalist died on October 2 at its consulate in Istanbul.
A member of the team then dressed in Khashoggi's clothes and walked out of the building to make it appear as if he had left the consulate, the official said.
"As long as there's a continuing investigation, as long as we don't know what happened, I believe there is no basis for positive decisions on weapons exports to Saudi Arabia", Foreign Minister Heiko Maas said in an interview with broadcaster ARD. "So, what we would rather do is support the investigation, find out what happened".
Worldwide outrage over Khashoggi's October 2 slaying at the hands of Saudi officials, under still-disputed circumstances, has marked the greatest crisis in the 33-year-old's rapid rise, already tarnished by a catastrophic war in Yemen and a sweeping roundup of Saudi businessmen and activists.
"Nothing can justify this killing and we condemn it in the strongest possible terms", Germany, Britain and France said in their joint statement on Sunday. "It would be very foolish of Saudi Arabia to forfeit the trust of the oil market earned over decades by injecting politics into their oil policy".
Turkish government sources have claimed that Mr Khashoggi, a critic of Crown Prince Mohammed bin Salman and the Saudi government, was tortured and murdered by a hit squad flown in from Riyadh.
"Do I think he did it?" The existence of such evidence has been reported in Turkish media in a series of leaks, though Turkish officials have yet to confirm they have recordings.
Earlier on Friday, Ms Sanders said Secretary of State Mike Pompeo had spoken to the Crown Prince and briefed the president and John Bolton, Mr Trump's national security adviser.
However, Top American lawmakers have said the Saudi statement was not credible and demanded action against the Arab nation.
Saudi Arabia is the UK's key ally in the region and also a significant trading partner. But the prince himself, protected by his 82-year-old father, King Salman, has been tapped to lead a panel to reform the kingdom's intelligence services, a sign he will remain next in line to the throne.