President Donald Trump speaks to the media before leaving the White House in Washington, Tuesday, Nov. 20, 2018, to travel to Florida, where he will spend Thanksgiving at Mar-a-Lago. (AP Photo/Manuel Balce Ceneta)

Washington - US President Donald Trump's backing of Saudi Arabia following the murder of journalist Jamal Khashoggi has sparked a backlash from members of Congress who insist the US consider additional sanctions and further investigation into the killing.

Both Republicans and opposition Democrats weighed in after Trump said he would stand by the US relationship with Saudi Arabia, citing the need for a strong ally in the Middle East, its partnership in the fight against terrorism and hundreds of billions of dollars of business deals.

Republican Senator Bob Corker, chairman of the Senate Foreign Relations Committee, said the position was akin to the White House acting as a public relations firm for Saudi Crown Prince Mohammed bin Salman, and said Congress would consider everything at its disposal to respond, including requiring by law the determination of Mohammed's role in the dissident Saudi's killing.

Corker joined with Senator Bob Menendez, a Democrat, in calling on Trump to clarify by February whether the crown prince is responsible for the murder, which took place in the Saudi consulate in Istanbul early last month.

Republican Senator Lindsey Graham also advocated "serious sanctions" against members of the Saudi royal family.

Representative Eliot Engel, a Democrat on the House Foreign Affairs Committee, accused Trump of "trying to sweep bad acts under the rug."

Engel also said Trump's backing of Saudi Arabia cast doubt on the ability of US intelligence, which has not yet issued its report on the Khashoggi murder.

Trump, who is in Florida for the Thanksgiving holiday, on Wednesday thanked Saudi Arabia, pointing to a drop in the price of oil and saying on Twitter it was "Like a big Tax Cut for America and the World."