British Prime Minister Theresa May has urged Saudi Arabia’s de facto ruler to hold the killers of Jamal Khashoggi to account and to ensure that Riyadh cooperates fully with Turkey, her office said Friday.

May held talks with Crown Prince Mohammed bin Salman on the sidelines of the G20 summit in the Argentine capital of Buenos Aires.

"The prime minister stressed the importance of ensuring that those responsible for the appalling murder of Jamal Khashoggi are held to account and that Saudi Arabia takes action to build confidence that such a deplorable incident could not happen again,” her office said.

May also encouraged bin Salman to ensure that Saudi Arabia will cooperate fully with Turkish authorities and work to “bring both investigations to an acceptable close”.

Khashoggi, a Saudi journalist working for The Washington Post, was killed shortly after he entered the Saudi Consulate in Istanbul on Oct. 2.

After saying he had left the consulate alive, Saudi Arabia admitted weeks later that he was killed there, blaming his death on a group of rogue Saudi operatives.

May also asked Saudi Arabia to end the conflict in Yemen and “bring relief to millions threatened by famine” during her meeting with the crown prince.

Impoverished Yemen has been wracked by conflict since 2014, when Houthi rebels overran much of the country, including the capital, Sanaa.

The conflict escalated in 2015 when Saudi Arabia and its Sunni Arab allies launched a military campaign aimed at rolling back Houthi gains in Yemen and shoring up the country’s Saudi-backed government.

The war has resulted in a collapsed economy and a cholera outbreak that has affected over 1.1 million people.

Riyadh has repeatedly accused the Houthis of acting as a proxy force for Iran, Saudi Arabia’s arch-foe in the region.