Updates with national security adviser's comment throughout

By Heejin Kim

SEOUL, May 6 (Reuters) - South Korea's presidential office said on Wednesday it had suspended a review of whether to participate in a U.S. operation to escort ships through the Strait of Hormuz after President Donald Trump put the mission on hold.

A Blue House official also said it was still unclear if a South Korean-operated vessel that suffered an explosion and caught fire on Monday had been attacked in the strait.

Trump had earlier urged Seoul to join his "Project Freedom" initiative to free up navigation, claiming that Iran fired shots at a ​Korean-operated ship and other targets as the U.S. launched its operation to open the strait.

"After checking additional information, it seems to be unclear whether the vessel was attacked," Wi Sung-lac, South Korea's presidential national security adviser, told a briefing.

He said the ship did not seem to be listing after the fire, which started in the engine room and was extinguished hours later. None of the 24 crew members was injured.

The ship's operator, South Korea's HMM 011200.KS, said on Wednesday it had secured a vessel to tow the Panama-flagged bulk carrier to a port in Dubai for an inspection.

The carrier was expected to arrive in Dubai on Thursday night or Friday morning Seoul time, the company said.

In normal times, about a fifth of the world's oil and liquefied natural gas passes through the strategic waterway.

South Korea ⁠has been cautious about becoming too directly embroiled in the Middle East conflict, but the presidential Blue House said on Tuesday it was reviewing Trump's suggestion that Seoul participate in the plan to free up navigation.

Trump later said he would pause the operation, citing "great progress" toward a comprehensive agreement with Iran.

"We don't believe a review of Trump's call to participate in Project Freedom is needed at this point," Wi said.

The government had already been examining another U.S. proposal to join an international framework for freedom of navigation, dubbed the Maritime Freedom Construct (MFC), he said.

"Freedom of navigation and international safety is important to us," Wi said, adding Seoul would monitor international developments in this area and assess whether to take part.

The South Korean government has said 26 South Korean-flagged vessels were stranded around the Strait of Hormuz.