SCOTTSDALE, Ariz. (Reuters) - The White House said on Friday it would press for justice after Saudi Arabia announced that journalist Jamal Khashoggi had died in the kingdom’s consulate in Istanbul and that 18 Saudis had been arrested in connection with his death.

A TV journalist reports outside the Saudi Arabia's consulate in Istanbul, Turkey October 20, 2018. REUTERS/Huseyin Aldemir

“We will continue to closely follow the international investigations into this tragic incident and advocate for justice that is timely, transparent, and in accordance with all due process,” White House spokeswoman Sarah Sanders said in a statement.

“We are saddened to hear confirmation of Mr. Khashoggi’s death, and we offer our deepest condolences to his family, fiancée, and friends,” she added.

But members of Congress voiced skepticism about the Saudi public prosecutor’s explanation that a fight broke out between Khashoggi and people who met him when he went to the Saudi consulate in Istanbul on Oct. 2 and that the altercation led to his death.

“To say that I am skeptical of the new Saudi narrative about Mr. Khashoggi is an understatement,” Republican U.S. Senator Lindsey Graham, said on Twitter. Graham, who has been sharply critical of Saudi Arabia after Khashoggi’s disappearance, is a close ally of President Donald Trump.

“First we were told Mr. Khashoggi supposedly left the consulate and there was blanket denial of any Saudi involvement. Now, a fight breaks out and he’s killed in the consulate, all without knowledge of Crown Prince,” Graham said.

“It’s hard to find this latest ‘explanation’ as credible,” he added.

Members of Congress have the power to block U.S. arms sales to Saudi Arabia. Trump said last week he saw no reason to cut off weapons sales to Saudi Arabia in response to Khashoggi’s disappearance.

But earlier on Friday, speaking prior to the Saudi announcements, Trump said he might consider sanctions against Saudi Arabia over the journalist’s disappearance, while emphasizing the importance of the U.S.-Saudi relationship. Trump said the U.S. Congress would be involved in determining the American response.

Trump and his administration have drawn criticism for being slow to rebuke Riyadh, and the White House statement on Friday did not indicate a particular stance on the Saudi announcement.

Democratic U.S. Senator Richard Blumenthal told CNN the Saudi explanation “absolutely defies credibility” and he called for an international investigation of Khashoggi’s death.

“The Saudis very clearly seem to be buying time and buying cover. But this action raises more questions than it answers and there is no way the world will wait for 30 days for a Saudi investigation to be done,” Blumenthal said.

Democratic Senator Chris Van Hollen, called the Saudi statement a cover-up.

“The United States must not be complicit in this cover-up. Looking forward to what our intelligence agencies have to say,” Van Hollen said.