The US would not comment on the alleged attack on an Iranian oil tanker, but is preparing to send more troops and military hardware to Saudi Arabia.

Hours after Iranian state media reported the 160,000-dwt suezmax tanker Sabiti (built 1999) had suffered two explosions, the US announced another 3,000 forces would head to Saudi Arabia as a defensive measure.

"We've seen the reports about the tanker off the coast of Sudan and I don't have any comment on it," US special representative for Iran Brian Hook said in a press briefing Friday.