Jakarta. The Indonesian government has denied that flag issues had complicated the passage of its tankers through the Strait of Hormuz.

Two vessels belonging to the state-run oil giant Pertamina still can’t exit the blocked Strait of Hormuz, which Iran holds a stranglehold on. One of the trapped Pertamina tankers — known as the Gamsunoro — is sailing under a Panama flag. Another tanker, the Pertamina Pride, is flying the Singaporean flag, according to the ship tracking website VesselFinder. The practice of ships using other countries’ flags is known as “flag of convenience”. This is common among international shipowners who wish to escape stricter marine regulations and pay low or no taxes.

Foreign Ministry spokeswoman Yvonne Mewengkang said that the delayed passage had nothing to do with the flag problems.

“Our communications with the Iranian side indicate that there is no issue with the flag of convenience by the Indonesian tankers. We are still in the process [of securing the passage],”  Yvonne told a press briefing in Jakarta on Thursday.

Traffic in the global energy lifeline remains uncertain amid a fragile Iran-US ceasefire. Iran has blocked the Strait of Hormuz in retaliation for US-Israeli strikes that started in late February, disrupting the waterway that has 25% of the world’s seaborne oil trade. Vahd Nabyl A Mulachela, another spokesperson at the Foreign Ministry, said that the “Strait of Hormuz must remain safe, open, and passable by international ships in accordance with international laws.”

“Indonesia rejects all forms of threats to merchant ships. The safety of the seafarers must be a top priority,” Nabyl said.

According to Nabyl, Indonesia is still following up on the “positive signals” that Tehran had given to allow the two Pertamina tankers to pass through the strait. However, the actual exit remains subject to technical preparedness, including insurance for safe transit.

Pertamina Pride was supposed to transport light crude oil to Indonesia. Gamsunoro was serving a third-party cargo. Both tankers are in the Persian Gulf. The Strait of Hormuz is the only maritime exit out of the Persian Gulf. Jakarta recently clinched an undisclosed amount of Russian crude and liquefied petroleum gas (LPG) to augment domestic supplies amid the traffic disruptions.