The United Nations said Friday it is encouraged that a U.N. team may be able to visit an oil tanker loaded with 1.1 million barrels of crude oil that is moored off the coast of Yemen, posing a serious risk to Red Sea marine life, desalination plants and shipping.

Houthi rebels, who control the area where the ship is moored, have denied U.N. inspectors access to the vessel.

But U.N. spokesman Stephane Dujarric said "the local authorities recently signaled they would approve a U.N. mission to the site."

"We are following up with them now to confirm details," he said. "We hope logistical arrangements will be quickly completed so this work can begin."

Internal documents obtained by The Associated Press last month show that seawater has entered the engine compartment of the FSO Safer tanker, which hasn't been maintained for over five years, causing damage to the pipelines and increasing the risk of sinking. Rust has covered parts of the tanker and the inert gas that prevents the tanks from gathering inflammable gases, has leaked out.

According to AP's June 26 report, experts say maintenance is no longer possible because the damage to the ship is irreversible.

Dujarric said the U.N. remains "extremely concerned" about the tanker.

He said water in the engine room "could have led to disaster" and "a temporary fix has been applied, but it is unclear how long this might last." He gave no further details.

Dujarric said "the assessment mission will conduct feasible light repairs and will help to determine the appropriate next steps."

The Iranian-backed Houthi rebels are in control of the western Red Sea ports, including Ras Issa, 6 kilometers (3.7 miles) from where the FSO Safer tanker has been moored since the 1980s. They are at war with the internationally recognized government, which is backed by a Saudi-led coalition and the United States. President Abed Rabbu Mansour Hadi is in exile in Saudi Arabia and his government in disarray.

The floating tanker is a Japanese-made vessel built in the 1970s and sold to the Yemeni government in 1980s to store up to 3 million barrels pumped from oil fields in Marib, a province in eastern Yemen, before it was exported. The ship is 360 meters (1,181 feet) long with 34 storage tanks.