President Donald Trump has said the US will inflict "severe punishment" on Saudi Arabia if the kingdom is found to be responsible for the death of journalist Jamal Khashoggi.
He said he would be "very upset and angry if that were the case", but ruled out halting big military contracts.
Mr Khashoggi, a critic of the Saudi government, vanished on 2 October after visiting its consulate in Istanbul.
Saudi Arabia dismissed allegations that it ordered his killing as "lies".
The interior minister said on Friday that the kingdom was keen to uncover "the whole truth", stressing reports "about orders to kill" are "baseless".
A Turkish security source has told the BBC that officials had audio and video evidence proving Mr Khashoggi, who writes for the Washington Post, was murdered inside the consulate.
The country's Foreign Minister, Mevut Cavusoglu, said Saudi Arabia was not yet co-operating with the investigation.
He urged it to do so and allow Turkish officials to enter the consulate.
What did Mr Trump say?
In an interview with CBS News, Mr Trump said that, if true, the fact that a journalist was murdered was "terrible and disgusting".
"We're going to get to the bottom of it and there will be severe punishment," he said.
"As of this moment, they deny it vehemently. Could it be them? Yes," he added.
However, he said that there were "other ways of punishing" than cancelling military contracts, which powers like Russia and China were interested in.
"I don't want to hurt jobs, I don't want to lose an order like that," Mr Trump said.
Speaking to journalists later, Mr Trump said his first hope had been that Mr Khashoggi was not killed, but "maybe that is not looking good".
He would probably call Saudi King Salman "tonight or tomorrow", he added.
What other reaction has there been?
On Friday UN Secretary General Antonio Guterres told the BBC that "this kind of incident is multiplying" and urged the international community to respond.
He said that, once it was clear what had happened to Mr Khashoggi, governments should decide "in the appropriate way" whether to attend an investment conference to be held in the Saudi capital Riyadh this month.
Jim Kim, the head of the World Bank, has already withdrawn from the event.
Sir Richard Branson, the head of Virgin, has said he is suspending his role as director of two tourism projects.
He has also halted discussions about a $1bn (£750m) investment by the Saudi sovereign wealth fund into Virgin's space ventures.
What do Turkey's recordings reveal?
The latest reports suggest an assault and a struggle took place in the consulate.
A Turkish security source has confirmed to BBC Arabic the existence of an audio and a video recording. What is not clear is if anyone other than Turkish officials has seen or heard them.
On Saturday Turkish pro-government newspaper Sabah said the audio recording came from an Apple Watch Mr Khashoggi was wearing at the time.
The recording was recovered from his iPhone, which he gave to his Turkish fiancée Hatice Cengiz when he entered the consulate, and his iCloud account, the paper added.
However, it was not clear how the data could have been uploaded from the watch to iCloud.
One source is quoted by the Washington Post as saying men can be heard beating Mr Khashoggi; it adds that the recordings show he was killed and dismembered.
"You can hear his voice and the voices of the men speaking Arabic," a separate source told the Post, which employed Mr Khashoggi as a contributing columnist. "You can hear how he was interrogated, tortured and then murdered."
Turkish TV has already broadcast CCTV footage of the moment Mr Khashoggi walked into the consulate for an appointment at which he was due to receive papers for his forthcoming marriage to Ms Cengiz.