ANKARA - Saudi Arabia has committed to conducting a complete investigation into the disappearance of journalist Jamal Khashoggi, US Secretary of State Mike Pompeo said on Wednesday.

Pompeo said he would meet with President Tayyip Erdogan in the Turkish capital Ankara, two weeks after Khashoggi vanished when he visited the Saudi consulate in Istanbul to collect documents he needed for his planned marriage.

Earlier, President Donald Trump gave Saudi Arabia the benefit of the doubt in Khashoggi's disappearance, while US lawmakers pointed the finger at the Saudi leadership and Western pressure mounted on Riyadh to provide answers.

In Saudi Arabia, Pompeo met with Saudi King Salman, the crown prince and the foreign minister.

"In each of those meetings I stressed the importance of them conducting a complete investigation into the disappearance of Jamal Khashoggi. They made a commitment to do that," he told reporters travelling with him after boarding the plane for Ankara.

"They said it would be a thorough, complete and transparent investigation," he said. "They indicated they understood that getting that done in a timely, rapid fashion so they could begin to answer important questions."

Turkish officials have said they believe Khashoggi was murdered and his body removed, which the Saudis have strongly denied. Khashoggi was a US resident who wrote columns for the Washington Post and he was critical of the Saudi government, calling for reforms.

Earlier, in a Twitter post, Trump said Saudi Arabian Crown Prince Mohammed bin Salman denied knowing what happened in the Saudi consulate.

"I think we have to find out what happened first," Trump told the Associated Press in an interview on Tuesday. "Here we go again with, you know, you're guilty until proven innocent. I don't like that."

"They made no exceptions to who they would hold accountable. They were very clear: they understand the important of this issue, they are determined to get to the bottom of it," Pompeo told reporters.

Asked whether they said Khashoggi was alive or dead, Pompeo said: "They didn't talk about any of the facts."

The case of Khashoggi has become a major source of tension between Saudi Arabia and the West.

Khashoggi has been missing since he entered the Saudi Consulate in Istanbul on Oct. 2. Unconfirmed reports said that Khashoggi was likely killed inside the compound, a claim denied by Saudi officials as "baseless."

Earlier on Monday, investigators entered the Saudi consulate in Istanbul. A Saudi delegation reportedly had entered the consulate one hour before the Turkish police arrived and appeared still to be inside as the search was conducted.