UN Secretary-General Antonio Guterres is deeply concerned about the condition of the Safer oil tanker moored off the western coast of Yemen and asks for UN access for assessment, said his spokesman on Friday.

The secretary-general urges the removal of any obstacles to the efforts needed to mitigate the dangers posed by the tanker without delay, said Stephane Dujarric, the spokesman, in a statement.

Guterres specifically calls for granting independent technical experts unconditional access to the tanker to assess its condition and conduct any possible initial repairs. This technical assessment will provide crucial scientific evidence for next steps to be taken in order to avert catastrophe, said the statement.

The aging tanker has had almost no maintenance since 2015 and risks causing a major oil spill, explosion or fire that would have catastrophic environmental and humanitarian consequences for Yemen and the region, it said.

In particular, a potential oil leak into the Red Sea would severely harm Red Sea ecosystems relied on by 30 million people across the region. It would moreover force the closure of Hodeidah port for many months, which would exacerbate Yemen's already severe economic crisis and cut off millions of people from access to food and other essential commodities, it warned.

The Houthi rebels, who control the territory where Safer is moored, first indicated on July 5 that they would allow an inspection and emergency repair team to board the floating oil storage and offloading vessel. An official UN request was sent on July 14.

One month later, the United Nations is still waiting for permission from Houthi rebels, who have recently come back to the United Nations with a range of technical follow-up questions, said Dujarric on Wednesday.

Earlier on Friday, Guterres' press office said the issue should not be politicized.

"Averting this calamity should not be politicized. It is about people's lives and futures," said the office in a note to correspondents.

The Yemeni people are already facing impossible odds: a war, a free-falling economy, diseases, shattered public institutions, unreliable infrastructure, hunger, and uncertain futures. The Safer oil tanker is a solvable problem and does not need to be added to their many other burdens, it said.

On May 27, 2020, seawater leaked into the engine room, threatening to destabilize and sink the entire vessel, and potentially releasing all the 1.1 million barrels of crude oil into the sea. A temporary fix by divers from the Safer corporation succeeded in containing the leak. But the fix is unlikely to hold for very long, warned the United Nations.

"Planning and executing a sustainable solution will not be possible without independent experts first assessing the damage. And the assessment cannot be completed if the experts are not granted the required visas and permits to deploy to the tanker."