Despite the global outrage at Saudi Arabia, Mr. Mnuchin said he did not intend to scold his Saudi counterparts about rights abuses.

“I’m sure I’ll be speaking with the president before I go there,” he said. “If he has a message that he wants me to deliver, I will obviously deliver it. That is not the focus of my trip.”

While Mr. Trump has acknowledged that the Saudi government was not forthright in its explanations of what happened to Mr. Khashoggi, he has continued to express admiration for Mohammed bin Salman, the crown prince, as someone who loves his country.

The prospect of the United States’ imposing sanctions on Saudi Arabia has raised concern that the country could slow oil production in retaliation. Mr. Mnuchin said, however, that he had no reason to believe that Saudi Arabia would not honor its oil-production commitments.

Mr. Mnuchin planned to visit the Terrorist Financing Targeting Center, which the United States leads with Saudi Arabia, and meet with the Saudi finance minister, the energy minister and other economic officials in Riyadh.

A year ago, Mr. Mnuchin made his first trip as secretary to Saudi Arabia to speak at the investor conference and unveil the terrorist financing center. He said that the initiative still needed more work and that he planned to keep coming back to oversee its progress.

In Israel, the Treasury secretary was on the first stop of a six-country trip through the Middle East focused on the battle against terrorist financing. He is also visiting Jordan, the United Arab Emirates, Qatar and Kuwait.