A senior member of the Saudi royal family has warned against a US troop withdrawal from Syria.
Prince Turki al-Faisal told the BBC the action would have a negative impact, further entrenching Iran, Russia and the rule of President Bashar al-Assad.
US President Donald Trump announced in December that it was time to bring US troops home from Syria.
Prince Faisal was speaking ahead of US Secretary of State Mike Pompeo’s visit to Riyadh.
Mr Pompeo is on a tour of the Middle East, and has already visited Iraq, Jordan, Egypt and Bahrain.
What did Prince Faisal say?
He said that the world community was guilty of neglecting the Syrian people and the US troop withdrawal would make things worse.
“The US actions from my perspective is that it is going to further complicate, rather find any solutions to it and further entrench not only the Iranians, but also the Russians and Bashar al Assad, so from the perspective it is a very negative development,” he said.
The prince added that the departure of Defence Secretary James Mattis in December was unlikely to help matters either.
“Obviously he disagreed with the administration on Syria policy so in that context his remaining would have been a more positive sign of commitment to that policy,” he said.
The prince is no longer a member of the Saudi government, but has decades of experience within it.
BBC State Department correspondent Barbara Plett says that while he is most likely reflecting Saudi official opinion he is not speaking for the government.
What is Mike Pompeo going to talk about?
US media report that he is expected to discuss Iran and the conflicts in Yemen and Syria during his time in Riyadh, as well as seeking an update on the investigation into the murder of journalist Jamal Khashoggi.
He said at a news conference in Qatar that he would ask Crown Prince Mohammed bin Salman to hold Khashoggi’s killers “accountable”.
The trip to Riyadh comes just three months after the murder of Khashoggi, a critic of Saudi’s rulers, at the Saudi consulate in Istanbul.
Riyadh has admitted he was murdered there, but denied suggestions that the crown prince was involved. It had initially maintained that the writer left the consulate unharmed.
“We will continue to have a conversation with the crown prince and the Saudis about ensuring accountability,” Mr Pompeo said at a news conference in Qatar on Sunday.
Timeline: Jamal Khashoggi’s death
How the story unfolded
2 October 2018
Jamal Khashoggi enters the Saudi consulate in Istanbul. His fiancée Hatice Cengiz waits outside, but Khashoggi doesn’t emerge.
4 October 2018
In its first statement, Saudi Arabia says Khashoggi disappeared after leaving the consulate, and that it is trying to establish what happened to him.
6 October 2018
Khashoggi’s employers, the Washington Post, report that Turkish intelligence believe he was killed inside the consulate by a 15-man team sent from Saudi Arabia.
10 October 2018
CCTV footage showing the alleged hit squad arriving in Turkey is aired by Turkish media.
13 October 2018
Saudi Arabia attacks “lies and baseless allegations” and repeats it did not kill Khashoggi. The BBC learns Turkey has an audio recording indicating he was killed in the consulate.
15 October 2018
Donald Trump speaks to Saudi King Salman, who denies his country killed Khashoggi. Trump suggests “rogue killers” may be responsible.
20 October 2018
For the first time, Saudi Arabia admits Khashoggi is dead, claiming he died in a fight. This is met with wide scepticism. Two senior Saudi officials are fired.
22 October 2018
Saudi Arabia gives a new account, denying reports that Crown Prince Mohammed bin Salman ordered the killing, saying Khashoggi was murdered in a “rogue operation”. Footage emerges of a body double leaving the Saudi consulate dressed in Khashoggi’s clothes.
16 November 2018
The Washington Post reports the CIA has concluded Mohammed bin Salman ordered the killing. Trump later contradicts this, saying the CIA did not conclude the crown prince was responsible.
22 November 2018
France, like Germany and the UK, bans all the Saudi suspects from its territory. Germany also stops arms sales to Saudi Arabia.
What else has Pompeo discussed on his trip?
Speaking in Qatar, America’s most senior diplomat also called for more unity between Arab states, urging an end to the 18-month economic boycott of Qatar.
Saudi Arabia, the UAE, Bahrain and Egypt – all US allies – cut ties with Qatar in June 2017, accusing the oil-rich state of supporting the region’s terrorist groups and Iran – Saudi Arabia’s main regional rival.
Qatar denies that, and has accused its neighbours of seeking regime change.
Mr Pompeo’s trip is intended to reassure America’s Middle East allies of its commitment to the region.
On 15 January the US secretary of state will visit Kuwait, where he is expected to sign an agreement to “boost the strategic dialogue between the two countries”, according to Kuwait’s state news agency.