Khashoggi, who has been missing since he entered the Saudi consulate in Istanbul on October 2, had been banned from writing in the pan-Arab Al-Hayat newspaper following his defence of the Muslim Brotherhood, which Riyadh has blacklisted as a terror organisation.
Investigators have made no claims about where Khashoggi's remains may be, and some police units continue to believe there is not enough evidence to state authoritatively that the 59-year-old is dead.
The heir to the throne went on to say Trump's comments about Saudi Arabia not paying its way militarily were untrue, as it had spent billions of dollars on United States arms.
"So Saudi Arabia needs something like around 2,000 years to maybe face some dangers. I don't believe he's been killed!" his fiancée Hatice wrote on Twitter late Saturday night.
Speaking at a campaign rally in Mississippi, Trump had said, "I love the king, King Salman, but I said, 'King, we're protecting you". We stand in solidarity with the two Reuters reporters imprisoned in Myanmar. "You have to pay for your military, you have to pay'".
Making another significant investment in SoftBank's next Vision Fund would help the PIF boost its assets, which have already risen to more than $300 billion, Prince Mohammed said.
"I love working with him", Prince Mohammed said in an interview at the royal palace in Riyadh on Wednesday.
But bin Salman downplayed Trump's remarks, saying "you have to accept that any friend will say good things and bad things". You will have misunderstandings.
Mohammed bin Salman had led the 5 per cent listing, which he hoped would raise $100bn, until it was suddenly put on hold earlier this year in favour of a deal that would see Aramco acquire a majority stake in petrochemicals firm SABIC from his sovereign fund the Public Investment Fund (PIF).
"We export as much as two barrels for any barrel that disappeared from Iran recently", Prince Mohammed said.
"It's not free armament".
"Ever since the relationship started between Saudi Arabia and America, we've bought everything with money".
Saudi Arabia invited a group of journalists into the Istanbul mission on Saturday, in an effort to show that Khashoggi was not on the premises.
Speaking at an event in Riyadh a year ago, Son said that investments made by the first Vision Fund were already paying off.
"And I believe, and I'm sorry if anyone misunderstands that, but I believe President [Barack] Obama, in his eight years, he worked against many of our agenda - not in Saudi Arabia, but also in the Middle East".
"God willing, we will not be faced with the situation we do not desire", he said when asked by journalists about Khashoggi.
During his speech to the UN General Assembly, the U.S. president in a similar vein cautioned other countries against taking advantage of the United States. This announcement settles the projected date of the Initial Public Offering (IPO) of the company, nearly two years after it was first announced by the crown prince that Aramco would be turned into a public holding. "It's totally different. Canada, they gave an order to Saudi Arabia on an internal issue. More than that, all these issues we look at them seriously and we're trying to be sure that no one is harmed as much as we can".