"Saudi Arabia, if we broke with them, I think your oil prices would go through the roof," Trump told reporters on Tuesday. "I've kept them down. They've helped me keep them down."
Trump issued a statement earlier on Tuesday saying the United States stands by Saudi Arabia after agents of the kingdom killed U.S. resident and journalist Jamal Khashoggi in a Saudi consulate in Istanbul, Turkey.
The CIA has reportedly concluded that Crown Prince Mohammed bin Salman, an ally to the Trump administration, ordered Khashoggi's death. On Tuesday, Trump cast doubt on that assessment, saying in his statement "maybe he did and maybe he didn't!"
The United States has sanctioned 17 individuals connected to the killing. U.S. lawmakers have called for the United States to suspend some arms sales to Saudi Arabia.
Trump's comments on Tuesday illustrate how his administration has relied on Saudi Arabia to pump more oil and convince a group of producers to increase output in order to keep prices low. Trump's declaration of support for Saudi Arabia comes just two weeks before OPEC, Russia and several other producers meet to decide whether to reverse course and cut production next year.
The cost of crude began rising earlier this year as Trump prepared to restore sanctions on Iran, OPEC's third biggest oil producer. On Tuesday, Trump said Saudi Arabia had helped him prevent oil prices from spiking above $100 a barrel.
"Right now we have oil prices in great shape. I'm not going to destroy the world economy, and I'm not going to destroy the economy for our country by being foolish with Saudi Arabia," he said.
"I think the statement was pretty obvious what I said. It's about America First."
In May, Trump pulled the United States out of a nuclear accord with Iran, against the wishes of U.S. allies in Europe that helped negotiate the deal alongside U.S. diplomats. Saudi Arabia is Iran's chief rival for regional influence and backed Trump's exit from the 2015 Iran nuclear deal.
U.S. sanctions on Iran's energy, banking and shipping sectors snapped back into place on Nov. 5. One month before that, oil prices spiked to four-year highs as the market braced for a potential shortage of crude.
That rally has since unwound, with crude futures plunging about 30 percent on concerns about a slowdown in global economic growth and the view that oil supply will outstrip demand next year. Trump's decision to allow some of Iran's biggest customers to continue buying crude from the Islamic Republic contributed to the pullback.
Saudi Arabia and its allies are now considering cutting output by 1 million to 1.4 million barrels per day to prevent a price-crushing crude glut. Trump recently took to Twitter to urge the Saudis and OPEC against throttling back output.
Trump also said he wants to preserve billions of dollars in potential U.S. arms sales to Saudi Arabia, which is facing mounting criticism for its invasion of neighboring Yemen. The conflict has created the world's worst current humanitarian disaster, with both the Saudi-led coalition and Iran -backed Houthi rebels accused of war crimes.
Democratic leaders lambasted Trump's statement on Tuesday.
"We should immediately end support to the Saudis in the war in Yemen and bring that conflict to an end, suspend arms sales to the Kingdom, and diminish our reliance on Riyadh regarding other matters in the region," said Rep. Adam Schiff of California, the ranking member of the House Permanent Select Committee on Intelligence.