"The United States intends to remain a steadfast partner of Saudi Arabia to ensure the interests of our country, Israel and all other partners in the region", the president added, noting Saudi investments in USA military equipment and other contracts.
Lee added that he hoped mounting fury at Saudi Arabia would become "an opportunity for the Congress to weigh in and say, let's halt our efforts in Yemen".
The International Rescue Committee, Oxfam America, CARE US, Save the Children, and the Norwegian Refugee Council said in a joint statement that 14 million people are at risk of starving to death in Yemen if the parties to the conflict do not change course immediately.
"That was the most glaring of inaccurate and wrong assessments, which led to a full-scale war with thousands being killed", he said, speaking at an event hosted by the Beirut Institute. "It's inconsistent with the intelligence I've seen", said Lee.
And the prince is also set to travel to the Tunisian capital on Tuesday, a presidential source in Tunis told AFP. Trump has brushed aside assessments by USA intelligence and other experts that the crown prince must have been involved in the high-level operation, and said he would maintain close relations with Saudi Arabia in part because of its oil wealth and its multi-billion-dollar purchases of US arms. "And if there are indicators coming from those intelligence agencies, he also needs to be involved in some sort of action".
Mr. Trump was ambiguous Thursday about assigning blame for Khashoggi's murder last month at the Saudi Arabian consulate in Turkey, citing the kingdom's importance as an ally and saying Crown Prince Mohammad Bin Salman has "vehemently" denied responsibility.
They stressed that: "Saudi Arabia is a country that is not governed by the law and does not have a credible and independent judicial system in its principles of justice. Strength is telling the truth even when it's hard".
Republican Senator Ben Sasse of Nebraska, a frequent Trump critic, said on Fox News, "Making the realist case (about the need for a U.S. -Saudi alliance) is a different thing than being so weak that we failed to tell the truth".
The Senate is expected to take up a bill this week from Lee and Sen.
Numerous U.S. lawmakers have said they intend to push for U.S. sanctions against Saudi Arabia because of Khashoggi's killing.