"We think the market is going to settle by Friday or Monday and correct itself", Steve Neely, president of fuel supplier Noil Petroleum, said.
Trump, alternating between aggressive and nonviolent reactions, said the USA could respond "with an attack many, many times larger" but also "I'm not looking at options right now".
Iranian Supreme Leader Ayatollah Ali Khamenei on Tuesday ruled out talks with the United States unless the Trump administration returns to the nuclear accord between Iran and the West that the United States abandoned previous year.
Iran rejected the USA "evidence", with a government spokesman saying now there was "absolutely no chance" of a hoped-for meeting between Iranian President Hassan Rouhani and President Donald Trump at the UN General Assembly next week. USA officials have not said what that information includes.
Satellite images of the attacked Saudi sites released by the United States afterward show damage done largely in a northern direction at the sites. Iran's allies in Yemen's civil war, the Houthi movement, claimed responsibility for the attacks. For decades, Saudi Arabia has been the oil market's great stabilizer, maintaining a large cushion of spare production capacity that can be tapped in emergencies, such as the 2011 war in Libya.
The increasingly complex conflict dovetails with the Trump administration's attempt to curb Iranian power through a "maximum pressure" campaign of crippling economic sanctions.
The new tensions have prompted critiques from regional analysts who say the Trump administration's policy of pulling out of the global nuclear deal and isolating Iran has backed the country into a corner.
According to Khamenei, Washington's policy of maximum pressure on Tehran will fail.
But Iranian officials have repeatedly said that the stifling sanctions must be removed before any talks can take place.
Iran's supreme leader said Tuesday "there will be no talks with the U.S.at any level".
Trump had warned that the U.S. was "locked and loaded" to respond to the attacks, but emphasised on Monday that he does not want a war.
Saudi Arabia, which has bought huge quantities of United States weaponry, is considered a strategic ally in the region, second to Israel, another bitter foe of Iran. "If the evidence points to direct Iranian involvement, it would constitute an unprecedented escalation". He said he did not want to kill what generals told him could be up to 150 people.
"So, while not impossible, it is implausible that the attack originated from Iran", he said. That, coupled with specifics on damage, may allow investigators to more firmly assign blame in just the latest murky attack in the region.
Iran has rejected U.S. charges that it was behind the strikes.
In a statement released following a weekly cabinet meeting, the ruler said that the worldwide community needed "to shoulder its responsibility in condemning the perpetrators" by "clearly confronting" those behind Saturday's attacks which targeted two Saudi Aramco sites, Abqaiq and Khurais, in eastern Saudi Arabia.
The attacks on crude-processing facilities at Abqaiq and Khurais resulted in the largest single supply disruption in half a century, and threw into question Saudi Arabia's status as supplier of last resort.
Oil markets continued to eye the situation carefully.