A day after Iranian forces seized a South Korean-flagged tanker, officials in Seoul were weighing up on Tuesday (January 5) whether to still send a senior diplomat to Tehran.
Vice Foreign Minister Choi Jong-kun's planned visit for Sunday is up for review now that the tanker has been seized in Gulf waters and its crew detained.
Tehran accused the boat of polluting the seaway, but the incident happened amid a spike in tensions between the two countries.
Tehran is demanding Seoul release Iranian funds frozen in South Korean banks due to U.S. sanctions.
Choi was supposed to be discussing those frozen funds, worth some 7 billion dollars, during his visit.
In Seoul a foreign ministry official told Reuters "the plan is unclear as of now" regarding Choi's visit.
The detained tanker is called the Hankuk Chemi, and is said to have been carrying 7,200 tons of ethanol.
It was seized by Iran's Revolutionary Guards and is being held at a port on the Iranian coast.
South Korea's foreign minister is making diplomatic efforts to secure its release.
The strait of hormuz lies between Iran and Oman, and almost a fifth of the world's oil passes through it.