One of the participants is Vice Foreign Minister Choi Jong-kun, who was previously expected to visit Tehran this coming weekend.

The owner of the vessel claimed that the boarding team consisted of staff - not law enforcement - from the armed Islamic Revolutionary Guard Corps (IRGC).

Seoul retains around $7 billion in frozen assets from Iran's Central Bank, confiscated after U.S. sanctions were imposed in 2018. Iran has identified the seizure of the tanker as an environmental pollution prevention enforcement operation, but analysts say that the seizure of the tanker is part of Tehran's effort to force the return of frozen funds.

It is currently investigating whether, as Iran alleges, the tanker - the Hankuk Chemi - may have breached any environmental regulations. It is also investigating whether Iran acted by boarding and seizing the vessel in the Hormuz Strait in breach of international law.

Also, South Korea sent a destroyer to the Strait, the Choi Young.

The seizure was also known as a warning to America's allies. Japan's transport ministry has warned Japanese shipping interests to exercise caution in the Gulf of Oman and the Strait of Hormuz, indicating the elevated threat level.

Maritime Business World