Trump's short conversation with Bin Salman came while the plenary session of the G-20 Summit, which has brought together in Buenos Aires the leaders of the world's 20 major economies, was closed to the press.
The two men "exchanged pleasantries," a senior White House official told reporters, speaking on condition of anonymity, Efe reported.
Asked about the encounter, Trump said they hadn't talked about anything important.
"We had no discussion. We might, but we had none," Trump said during a trilateral meeting with Japanese Prime Minister Shinzo Abe and Indian Prime Minister Narendra Modi.
The US president said last week that he would have a bilateral meeting with Bin Salman if both attended the G-20 Summit, but the White House decided not to program that meeting due to ostensible scheduling conflicts.
That meeting would undoubtedly have raised hackles in the US Congress, where the controversy continues about the October 2 murder of Khashoggi inside the Saudi Consulate in Turkey by a group of Saudi agents, including some known to be close to the crown prince.
Trump issued a long statement last week saying that Bin Salman's possible implication in the journalist's death was of little importance and that he had no plans to take punitive action against Riyadh because of the slaying.
The CIA has "nothing definitive" on the crown prince's involvement in the killing, Trump said, adding that "It could very well be that the Crown Prince had knowledge of this tragic event - maybe he did and maybe he didn't! That being said, we may never know all of the facts surrounding the murder of Mr. Jamal Khashoggi."
The president went on to say that the US "intends to remain a steadfast partner of Saudi Arabia to ensure the interests of our country, Israel and all other partners in the region."
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)