Iran acknowledged on Tuesday that its armed forces fired two Russian anti-aircraft missiles at a Ukrainian jetliner that crashed after taking off from Tehran's main airport earlier this month, killing all 176 people on board.

Qaboos had been unwell for years and underwent treatment in Belgium last month.

The global benchmark for crude oil rose above US$70 a barrel on Monday for the first time in over three months, with jitters rising over the escalating military tensions between Iran and the United States.

Speaking during a military parade, President Hassan Rouhani said that the presence of foreign forces in the Gulf could cause problems for the world’s “energy security.”

There had been reports about a possible meeting between President Donald Trump and his Iranian counterpart, Hassan Rouhani, during the upcoming U.N. General Assembly this month in New York.

Hassan Rouhani’s remarks signaled approval of U.S. President Donald Trump’s abrupt dismissal of John Bolton as national security adviser. Bolton had been hawkish on Iran and other global challenges.

State TV and the semi-official Fars news agency reported that seven crew members were detained when the ship was seized late Wednesday carrying 700,000 litres of “smuggled fuel” from Iran.

Both sides have called the interception of one another's ships "hostile acts" and "piracy."

The stand-off is a major international crisis for Britain's new Prime Minister Boris Johnson.

Panama began the flag withdrawal process on Friday after an investigation determined the tanker had "deliberately violated international regulations" by not reporting any unusual situation.