South Korea will send a government delegation to Iran “at the earliest possible date” to negotiate the release of a seized oil tanker and its crew, Seoul’s foreign ministry said Tuesday, AFP reported.

On Monday, Iran’s Revolutionary Guards reportedly said that the South Korean-flagged tanker Hankuk Chemi had been seized in Gulf waters with over 7,000 tonnes of ethanol, owing to continued violation of ‘maritime environmental laws’.

“A delegation… will be dispatched to Iran at the earliest possible date to try to resolve the matter through bilateral negotiations,” foreign ministry spokesman Choi Young-sam said, as per AFP reports, adding that vice foreign minister Choi Jong-kun would be going forward with his planned trip to Tehran.

The vice minister’s visit had been arranged prior to the seizure of the tanker, as tensions rise over the $7 billion worth of Iranian funds frozen in South Korea due to US sanctions.

“We need to verify the facts first and ensure the safety of our crew,” South Korea’s foreign minister Kang Kyung-wha said, amid speculation that Iran seized the ship as a means to pressure Seoul to release Iranian assets. 

“We are making diplomatic efforts for an early release,” she added, as per AFP reports.

According to Seoul’s defence ministry, a vessel carrying members of South Korea’s anti-piracy unit had arrived in waters near the Strait of Hormuz to ‘ensure the safety’ of its nationals.