U.S. President Donald Trump said Monday he was "not satisfied" with Riyadh's explanation of how journalist Jamal Khashoggi, a Washington Post contributor, died inside the Saudi consulate in Istanbul.

"I am not satisfied with what I have heard," Trump told reporters at the White House, adding that he thought more would be known about the controversial case "very soon."

After a phone call with Crown Prince Mohammed bin Salman, Trump also said "there's no reason" for Saudi Arabia's request for a month to complete an investigation into Khashoggi, adding "that's a long time."

Saudi Arabia's Foreign Minister Adel al-Jubeir said Tuesday the kingdom was committed to a thorough and complete investigation to get to the truth behind the killing of Khashoggi.

Saudi Arabia had sent a team to Turkey for a joint investigation and "uncovered evidence of a murder" in the Saudi Arabian consulate in Istanbul, the minister told a news conference in Indonesia during a state visit.

"We expressed commitment ... to see to it that the investigation is thorough and complete and the truth is revealed and those responsible will be held to account," al-Jubeir said at the joint news conference with his Indonesian counterpart.

"We will see to it ... that procedures and mechanisms are put in place to ensure that something like this can never happen again," he said.

Khashoggi went missing on Oct. 2 after he entered the Saudi Consulate in Istanbul.

After days of denying to know his whereabouts, Saudi Arabia on Saturday claimed Khashoggi died during a fight inside the consulate.

The kingdom's announcement that Khashoggi died in a "fistfight" was met with international skepticism and allegations of a cover-up to absolve the 33-year-old crown prince of direct responsibility.

On the day of Khashoggi's disappearance, 15 other Saudis, including several officials, arrived in Istanbul on two planes and visited the consulate while he was still inside, according to Turkish police sources. The 15 Saudis knew Khashoggi would enter the consulate to get a document he needed to get married, and once he was inside, the Saudis accosted Khashoggi, cut off his fingers, killed and dismembered the 59-year-old writer, according to media reports. All of the identified individuals have since left Turkey.

Saudi Ambassador to the U.S. Prince Khalid bin Salman, a brother of the crown prince, wrote Oct. 8 that Khashoggi had left, and that claims the kingdom "have detained him or killed him are absolutely false, and baseless."

Five Turkish employees of the consulate also gave testimony to prosecutors Monday. Istanbul's chief prosecutor had summoned 28 more staff members of the Saudi Consulate, including Turkish citizens and foreign nationals, to give testimony. Some Turkish employees reportedly said they were instructed not to go to work around the time that Khashoggi disappeared.