Officials at UN Headquarters are waiting for further developments in the disappearance -- and feared slaying -- of Saudi Arabian journalist Jamal Khashoggi before commenting further on the case, the chief UN spokesman said on Tuesday.

"The more facts we're able to get the more we would be able to comment," the spokesman, Stephane Dujarric, told reporters at a regular briefing.

When asked if UN Secretary-General Antonio Guterres had any personal contact with principals in the case, Dujarric said, "We're following the situation very closely. We're hearing the same reports that you are (hearing)."

"Once something official comes out from one party or another we will be able to comment further," he said. "At this point what is important is for the truth to be established for us to understand what has happened to Khashoggi."

The Washington Post columnist entered the Saudi consulate in Istanbul on Oct. 2 to obtain documents relating to the planned marriage of fiancee, Hatice Cenzig, of Turkey, according to published reports. She waited hours outside for Khashoggi's return but he never showed and he ultimately was declared missing.

Now, it has been alleged the journalist was killed in the consulate and his remains, in pieces, taken out of the country under diplomatic seal by a Saudi hit squad.

Earlier Tuesday, UN High Commissioner for Human Rights (UNHCHR) Michelle Bachelet in a statement issued in Geneva sought the lifting of diplomatic immunity of Saudi officials in the Turkish consulate.

"In view of the seriousness of the situation surrounding the disappearance of Khashoggi, I believe the inviolability or immunity of the relevant premises and officials bestowed by treaties such as the 1963 Vienna Convention on Consular Relations should be waived immediately," she said.

"Under international law, both a forced disappearance and an extra-judicial killing are very serious crimes, and immunity should not be used to impede investigations into what happened and who is responsible," Bachelet said. "Two weeks is a very long time for the probable scene of a crime not to have been subjected to a full forensic investigation."

"Given there seems to be clear evidence that Mr. Khashoggi entered the consulate and has never been seen since, the onus is on the Saudi authorities to reveal what happened to him from that point onwards," the high commissioner said.

She noted that Saudi Arabia and Turkey are both parties to the UN Convention Against Torture and Other Cruel, Inhumane or Degrading Treatment or Punishment.

As such, they are obliged to take all measures to prevent torture, enforced disappearances and other serious human rights violations, to investigate allegations of acts constituting these crimes, and to bring to justice those suspected of committing them, UNHCHR said.

U.S. President Donald Trump said Monday that he spoke with Saudi Arabia's King Salman by phone and that the monarch vehemently denied any knowledge about what happened. Trump also said he sent Secretary of State Mike Pompeo to meet with the king to discuss the disappearance.

Trump added that perhaps "rogue killers" were responsible.

Khashoggi, a Saudi national, has the status of permanent residence in the United States.

According to published reports, Pompeo said he had a "candid" meeting with the king and that the secretary of state was heading to Turkey.