Washington: US President Donald Trump says it looks like Iran was responsible for attacks over the weekend on Saudi Arabian oil plants but he is in no rush to respond and is still trying to find out who was behind the strikes.

"It's looking that way," Trump told reporters at the White House, adding that Washington is looking to "definitively" determine the culprit, but "pretty much already know[s]".

US President Donald Trump. Credit:AP

Several US cabinet officials, including Secretary of State Mike Pompeo and US Secretary of Energy Rick Perry, have blamed Tehran for the attacks, which cut 5 per cent of world crude oil production.

Iran has denied responsibility, with Iranian President Hassan Rouhani saying the strike was carried out by "Yemeni people" retaliating against attacks by the Saudi-led coalition in Yemen's four-year-old war.