UN chief Antonio Guterres has called for a "credible" investigation into journalist Jamal Khashoggi's murder in Saudi Arabia's consulate in Istanbul.
"It is absolutely essential to have a credible investigation and to have the punishment of those that were guilty," Guterres said at the Doha Forum conference in Qatar on Sunday.
The UN chief said he had no information on the case except what had been reported in the media.
Khashoggi, a Saudi contributor to the Washington Post, was killed on October 2 shortly after entering the kingdom's consulate in what Riyadh called a "rogue" operation.
Saudi Arabia has repeatedly rejected Turkish demands to extradite suspects connected to the murder of the journalist, a critic of Crown Prince Mohammed bin Salman.
'Ignoring murder' Turkey's foreign minister said on Saturday that his country would "not give up" on establishing the truth about the murder.
"We haven't received any new information or outcome of the investigation from the Saudi side," Mevlut Cavusoglu said, also in Qatar, which has been the target of a Saudi-led boycott since June 2017.
"Turkey will not give up on this, we will go to the end." Cavusoglu also said that many European countries are ignoring the murder, even as they promote freedom of expression and protection of journalists.
"Many European countries, who are promoting freedom of media, freedom of expression, are closing their eyes.
These countries, and the politicians, are putting some sanctions on people who are already in prison, who will never be visiting those countries.
At the same time, we haven't accepted any proposal to close this case," the foreign minister said at the Doha Forum.
Earlier this month, the minister said Turkey was in talks over a possible United Nations investigation into the killing that has provoked global outrage.
According to Turkey, a 15-member Saudi team was sent to Istanbul to kill Khashoggi, a palace insider turned critic of the Saudi leadership.
Riyadh has since detained 21 people over the murder. Despite speculation that the powerful crown prince ordered the hit, the kingdom has strongly denied he was involved.
The murder has damaged Riyadh's international reputation and Western countries, including the United States, France and Canada, have placed sanctions on nearly 20 Saudi nationals.
In addition, the US Senate voted on Thursday to approve a resolution calling for an end to US involvement in the Saudi-UAE-led military campaign in Yemen, setting the stage for a potential showdown next year between Congress and President Donald Trump over US military support for Saudi Arabia.
The Senate also approved a resolution saying that Prince Mohammed is responsible for the murder of Khashoggi.
US politicians have grown increasingly outraged as the number of civilians killed in Yemen by Saudi and UAE air attacks using US-made weapons has risen dramatically in the past two years.
The Saudi-UAE coalition launched an intervention in 2015 through a massive air campaign targeting Houthi rebels.