"I still cannot make human sense of it. I still cannot understand. I still feel that I`ll wake up," she said in emotional testimony to a hearing on international press freedom and the dangers of reporting on human rights.
Cengiz was the last person to see Khashoggi, a US resident and columnist for the Washington Post, before he went into the Saudi consulate in Istanbul on October 2 to obtain papers for their upcoming marriage.
He never left the building.
The Saudi journalist, a royal insider who became a critic of Crown Prince Mohammed bin Salman, was killed and dismembered inside the consulate by a team of Saudi operatives, provoking international revulsion.
"We still don`t know why he was killed. We don`t know where his corpse is," Cengiz said. She called for sanctions to punish Saudi Arabia and for Washington to push for the freedom of political prisoners held in the kingdom.
US authorities have concluded that responsibility for Khashoggi`s death went to the highest levels of the Saudi government. Riyadh denies the crown prince was involved.
Cengiz said she came to Washington hoping to help provoke a stronger reaction to her fiance` s death. She said President Donald Trump invited her to the White House months earlier, but that she had not come then because she was not confident about his response.
"I think we choose between two things ...," Cengiz told the subcommittee. "We can either go on as if nothing has happened ... or we can act, we can leave aside all interests, international interests and politics, and focus on the values for a better life."
The White House did not immediately respond to a request for comment. In the past, Trump has resisted imposing consequences such as strong sanctions. Saudi Arabia is considered an important partner in the Middle East and a counterweight to Iran.
Calling the United States "a fortress" protecting freedom of thought and human rights, Cengiz appealed for justice.
"I think it is a test for the United States and I believe it is a test that it can and should pass," she said.
'I still cannot make human sense of it. I still cannot understand. I still feel that I`ll wake up,' she said in emotional testimony to a hearing on international press freedom and the dangers of reporting on human rights.