Washington (CNN) Sen. Marco Rubio said Sunday that Treasury Secretary Steven Mnuchin should not attend an upcoming investment conference in Saudi Arabia amid an ongoing investigation into the country's possible involvement in the disappearance of Saudi journalist Jamal Khashoggi, who went missing earlier this month in Turkey.

"I don't think he should go," Rubio told CNN's Jake Tapper on "State of the Union," adding that he doesn't think any US officials should continue with their usual business in Saudi Arabia until Washington gets to the bottom of Khashoggi's disappearance.

"I don't think any of our government officials should be going and pretending it's business as usual until we know exactly what's happened here," Rubio, R-Florida, said.

Khashoggi, a columnist for The Washington Post, went into the Saudi consulate in Istanbul on October 2 to obtain paperwork that would allow him to marry his Turkish fiancée. He hasn't been seen in public since.

Rubio said that there will be "a very strong congressional response" if Khashoggi is found dead.

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