"This is very important for me, it is a very strategic issue for me. A major part of our oil sales must move from Kharg to Jask," Rouhani said in a televised speech as he inaugurated three new petrochemical plants in the southern energy hub of Asaluyeh.
To reach the oil terminal on Kharg Island, tankers must currently pass through the narrow Strait of Hormuz, slowing down deliveries. Iran has in the past repeatedly threatened to block the Strait of Hormuz - which is used by its Gulf rivals including Saudi Arabia - when faced with sanctions on its oil exports and possible military action by the US.
The latest threat was in July when Rouhani said Iran has always guaranteed the security of the strait but warned the US "should not play with the lion''s tail." Moving its terminal to the Oman Sea would in theory allow Iran to continue exporting oil even if the strait was closed.
The US pulled out of the 2015 nuclear deal in May and will reimpose sanctions on Iran''s oil sector in November.
The last time there was a major disruption in the flow of oil through Hormuz was in 1984 during the Iran-Iraq war when both sides attacked each other''s oil facilities and tankers. The strait is the world''s most important oil chokepoint with roughly 35 percent of all seaborne oil passing through it, according to the US Energy Information Administration.
Bloomberg reported that Iran exported 2.1 million barrels per day (bpd) of oil in August, but analysts say US sanctions could reduce sales to around 1 million bpd.