WASHINGTON (Reuters) – Several US Republican Senators rejected President Donald Trump's embrace against Saudi Arabia on Sunday after Saudi journalist Jamal Khashoggi was assassinated. Some members of his party said the congress needed to take additional measures.

FILE PHOTO: Saudi journalist Jamal Khashoggi speaks on September 29, 2018 at a Middle East Monitor event in London, UK. Middle East Monitor / Handout via REUTERS / File Photo

Trump promised to remain a "staunch partner" from Saudi Arabia last week, saying it was not clear whether Saudi Crown Prince Mohammed bin Salman knew of the plan to kill Khashoggi at the Saudi Consulate in Istanbul last month.

The President doubted the CIA's assessment that Crown Prince Mohammed had ordered the killing of Khashoggi and told reporters that the agency had not reached a final conclusion.

"I disagree with the assessment of the president. It's inconsistent with the information I've seen, "says Republican Sen. Mike Lee on NBC's Meet the Press.

He cited the murder of Khashoggi as another reason he protested against support for the Saudi Arabian war effort in Yemen

The United States imposed economic sanctions against 17 Saudi officials on November 15 for their role in the killing of Khashoggi, and senators from both major US parties introduced laws prohibiting the sale of weapons to Saudi Arabia over Khashoggi and its role in the civil war in Yemen.

Democratic US Representative Adam Schiff, who will lead the House Intelligence Committee in January when the Democrats regain control of the chamber in January, has promised to investigate Khashoggi and whether Trump's personal interests are his Saudi policy dictate.

"See, the president is not honest with the country regarding the killing of Jamal Khashoggi," Schiff said on CNN's State of the Union program. "What's driving that?"

Khashoggi, a Washington Post columnist and critic of the Crown Prince, was killed on 2 October. Riad initially rejected the knowledge of the disappearance of Khashoggi and offered contradictory explanations.

"I think we need to investigate this further," said Republican Senator Joni Ernst on CNN.

Ernst recognized the importance of Saudi Arabia as a strategic partner.

"But we are also a very strong nation when it comes to human rights when it comes to the rule of law," said Ernst.

"And if there's any indication that the prince was involved in the murder, we need to consider further action."

Senator Ben Sasse, a frequent Trump critic, criticized Trump's stance on Khashoggi's killing as weak.

"Making the realistic case is different from being so weak that we could not tell the truth," Sasse told Fox News Sunday. Crown Prince Mohammed helped to assassinate someone abroad, and it's not the power to mumble it. Strength tells the truth, even when it's hard. "

Other Republican Senators, including Lindsey Graham, Rand Paul, and Bob Corker, were relentless in their assessment of Saudi Arabia's participation in Khashoggi's assassination.

"I never thought I would see the day a White House appeared as a PR agency for the Crown Prince of Saudi Arabia," Corker, chairman of the Senate Foreign Relations Committee, said after Trump's comments on Tuesday on twitter.

Reporting by Doina Chiacu, Lucia Mutikani, Additional reporting by Roberta Rampton; Edited by Lisa Shumaker

Our standards:The Thomson Reuters Trust Principles.