Mattis to assure Arabs of US role in Mideast speech

US Defence Secretary Jim Mattis is to reaffirm America's role as a guarantor of stability in the Middle East, in a policy speech before Arab leaders on Saturday.

Mattis, who arrived in Bahrain on Friday, will address the Manama Dialogue at a time of strained US ties with key ally Saudi Arabia over the murder earlier this month of journalist Jamal Khashoggi.

Mattis will reiterate "our long term commitment to ensuring and helping these partners and allies... re-instill stability in a very chaotic region", said Principal Deputy Secretary of Defence for International Security Affairs Katie Wheelbarger.

He will call on Arab nations to "continue to look to the United states as your security partner of choice because you can rely on us and depend on us to be there long term", Wheelbarger told journalists travelling with Mattis.

The defence secretary's speech comes as Russia keeps up its military intervention in Syria and Washington accuses Tehran of sowing instability across the region.

Wheelbarger did not say whether Mattis would directly address the Khashoggi murder in his speech.

A critic of Saudi Arabia's powerful Crown Prince Mohammed bin Salman, Khashoggi was murdered after entering the Saudi consulate in Istanbul on October 2.

On Thursday, CIA Director Gina Haspel briefed US President Donald Trump on the latest developments in the investigation after a fact-finding mission to Turkey.

Pro-government Turkish media said that intelligence officers showed Haspel video images and audio tapes of Khashoggi's killing gathered from the consulate.

His murder has generated international outrage and undermined relations with Riyadh, which Washington depends on to counter Shiite power Iran's regional influence.

Bahrain is a key ally of both Saudi Arabia and the US, which bases its Fifth Fleet in the small island kingdom.

The Sunni-ruled kingdom in 2011 crushed a Shiite protest movement that had been inspired by the Arab Spring, accusing Iran of provoking unrest.