But in a follow-up tweet on Monday, Trump compared Iran's denial of involvement in the oil facility attacks to what the president called "a very big lie" regarding the downing of a USA drone earlier this year.
Iran will never hold talks with the United States and Washington's policy of maximum pressure on Tehran will fail, Supreme Leader Ayatollah Ali Khamenei said on Tuesday, according to state TV.
"The Iranians are gonna exhaust their playbook, I believe, before they come to the negotiating table".
Khamenei said Tuesday that Iran's leadership could not allow the strategy to work.
Those tensions have increased ever since Trump pulled the USA out of Iran's 2015 agreement with world powers that curtailed Iranian nuclear activities and the United States re-imposed sanctions that sent Iran's economy into a nosedive. "We want to find definitively who did this", he said.
USA secretary of state Mike Pompeo also said "emerging information indicates that responsibility lies with Iran". In a series of tweets after meeting with Trump and other senior national security officials, Esper said the administration was working with partner nations "to address this unprecedented attack and defend the worldwide rules-based order that is being undermined by Iran".
Shortly afterward, Trump ordered a military strike against Iran before changing his mind at the very last second.
Satellite photos released by the Trump administration show at least 17 impacts at two major Saudi oil installations - with what officials say was pinpoint accuracy - slashing Saudi Arabia's oil output by half.
He withdrew the USA from the nuclear pact between Iran and six world powers and reimposed sanctions that were lifted under the deal in return for Iran curbing its nuclear programme.
Keane said the Trump administration has no reason to sit down with the Iranians given the current situation.
The attacks reduced world crude oil production by 5 percent, sending prices soaring by as much as 19 percent after the incidents. The intraday jump was the biggest since the 1990-91 Gulf crisis over Iraq's invasion of Kuwait.
It's that sort of knee-jerk support for Saudi Arabia within American political ranks that makes a US military response troublingly likely.
The ministry added that Saudi Arabia "affirms that it has the capability and resolve to defend its land and people, and to forcefully respond to these aggressions".
He said at the White House that the USA is not looking at retaliatory options until he has "definitive proof" that Iran was responsible. "But we would certainly help them".
The Iranian president and foreign minister are going to attend an annual meeting of the United Nations general Assembly in NY later this month.
The attacks have raised questions about how the kingdom, one of the world's top spenders on weaponry, much of it supplied by US companies, was unable to protect oil plants from attack.
The Saudis invited United Nations and other global experts to help investigate, suggesting there was no rush to retaliate. Iran has repeatedly threatened that if it is prevented from selling its oil, other exporting countries will also suffer.
The US alleges the pattern of destruction suggested Saturday's attack did not come from neighboring Yemen, as claimed by Iranian-backed Houthi rebels there.
"It used to be that only governments had air forces, but drones have democratized violence from the sky", says another analyst, Bernard Hudson, a fellow on Persian Gulf security issues at Harvard University, quoted in the Washington Post newspaper.