President Trump earlier said the US was "locked and loaded" to respond (Picture: PA).
US President Donald Trump says it is "looking like" Iran was behind the attacks on oil facilities in Saudi Arabia but he has insisted he does not war.
President Trump said he is not looking at retaliating until he has "definite proof" that Iran was responsible.
However, he told reporters in the Oval Office that the US "is prepared" if the attacks warrant a response.
US Secretary of State Mike Pompeo also said that "emerging information indicates that responsibility lies with Iran".
The attack on the Abqaiq oil facility wiped out more than 5% of the world's oil production and sparked fears of an energy crisis in the region.
Global oil prices surged by nearly 20% following the bombing before settling down.
Iran has denied involvement in the attack which comes amid heightened tensions between Iran and the west, including the US, over the collapsing 2015 nuclear deal.
American officials released satellite images of the damage at the Abqaiq facility, claiming multiple cruise missiles and drone aircraft had been used in the attack.
The US alleged the pattern of destruction suggested Saturday's attack did not come from neighbouring Yemen, as claimed by Iranian-backed Houthi rebels based there.
A Saudi military spokesman later made a similar accusation, alleging "Iranian weapons" had been used in the assault.
The Houthi rebels, who have been targeted by a Saudi-led coalition since 2015, maintain they launched 10 drones that caused the extensive damage.
However, the US said the satellite images suggested the attack came from either Iraq or Iran.
Iran has rejected all allegations and a government spokesman says there is now "absolutely no chance" of a meeting between Iranian President Rouhani and the US President at the UN General Assembly next week.
The incident has prompted fears that new violence could emerge in the region which has been at the centre of high-profile attacks in recent months.
On Monday, President Trump said the US was "locked and loaded" to respond after the attack on the Saudi oil field.
Meanwhile, Houthi rebels have said Saudi oil sites remain as targets, warning foreign workers to stay away.