United States may help with Khashoggi investigation

US Attorney General Jeff Sessions says "serious evaluation" is being given over whether US law enforcement officials will aid in the investigation of the disappearance and alleged murder of Saudi journalist Jamal Khashoggi.

But Sessions said at an unrelated news conference on Tuesday that he would not comment further on the matter.

Sessions also declined to say whether he had any concerns over the current investigation.

Earlier, US President Donald Trump said he had spoken with Saudi Crown Prince Mohammed bin Salman and been assured that a "full" probe into the disappearance of the journalist was underway.

"Just spoke with the Crown Prince of Saudi Arabia who totally denied any knowledge of what took place in their Turkish Consulate," Trump tweeted. 

Read also: Saudi military coroner 'dismembered Khashoggi in front of consul'

US Secretary of State Mike Pompeo said early on Wednesday that Saudi leaders have promised to ensure accountability over the missing journalist, even as they denied any responsibility for his disappearance.

"My assessment from these meetings is that there is serious commitment to determine all the facts and ensure accountability, including accountability for Saudi Arabia's senior leaders or senior officials," Pompeo said in a statement after a day of talks Tuesday in Riyadh.

Turkish officials have said they believe Khashoggi was killed inside the consulate. Saudi Arabia has strongly denied this but has failed to explain the journalist's fate after entering its consulate building.

Earlier on Tuesday, a Turkish official confirmed that the body of Saudi journalist Jamal Khashoggi was cut into pieces after he was killed at the Saudi consulate in Istanbul two weeks ago.

Turkish authorities have also said they have recordings that indicate that Khashoggi was drugged and beaten before he was killed.

MBS has 'got to go'

Despite Trump's softer tone on Riyadh, influential senators have called for decisive action against Saudi Arabia, even calling for the ouster of Crown Prince Mohammed bin Salman.

"This guy is a wrecking ball. He had this guy murdered in a consulate in Turkey," Republican Senator Lindsey Graham told "Fox and Friends," one of the president's favourite news broadcasts.

Graham, discussing the feared killing of Saudi journalist and US resident Jamal Khashoggi, a critic of the monarchy, was backed by Marco Rubio, another of the top Republicans in the upper house, who described the crown prince as "young and aggressive."

"The MBS figure is to me toxic. He can never be a world leader on the world stage," Graham added, said he felt "personally offended" by the kingdom's leadership. 

"They have nothing but contempt for us. Why would you put a guy like me and the president in this box after all the president has done?" Graham fumed. "This guy has got to go."

'Strong and meaningful' action

As for the steps Trump should take, Graham said it was "up to the president" but pledged that Congress would "sanction the hell out of Saudi Arabia."

Congress "will act" in a way that will likely alter the US-Saudi relationship for the foreseeable future, Rubio asserted.

"What those specific measures are obviously is going to be up for debate, but they will be strong and meaningful," he added, saying he expected the administration would "follow suit.

Dianne Feinstein, a Democrat from California, meanwhile vowed to "not vote to support any arms sale to Saudi Arabia at this time, nor will I support US assistance for the Saudi-led war in Yemen."

"The United States must send a message that this killing will not go unpunished," she said in a statement.

Any initiative taken by the US Congress would have to wait until the 6 November elections, however, as both chambers are on recess until then.

Last week, top senators including Rubio and Graham sent a letter compelling the White House to report to Congress within 120 days with a determination about whether human rights abuses had occurred, and whether sanctions should be applied.

Congress has the power to temporarily block major arms deals, and several senators signalled they would consider doing so.