A ship is enroute to Yemen to pump oil from the decaying Safer tanker, the UN’s official coordinator for Yemen said on Saturday.

“The replacement vessel Nautica set sail from #Djibouti today at 09:45 en route to Yemen’s Red Sea coast to take on 1 million barrels of oil from the decaying #FSOSafer supertanker. I am excited to be aboard and for the start of the oil transfer next week!,” David Gressly, the UN resident coordinator for Yemen, posted on Twitter.

The Iran-backed Houthis finally allowed international engineers to board and inspect the deteriorating Safer tanker, moored off Hodeidah in western Yemen, after years of resistance against any operation to salvage the ship.

The 47-year-old Safer has had little or no maintenance since the war in Yemen began in 2015 and has deteriorated to such an extent that experts fear it is in imminent danger of springing a leak, catching fire, or exploding.

Environmentalists and officials have warned of large-scale environmental disaster if the ship’s cargo leaked into the ocean. Images of seawater flowing into the tanker’s rooms as rust eats away at the walls have grabbed international attention during the past three years.

Experts estimate a major leak from the Safer could severely damage Red Sea ecosystems upon which around 30 million people depend for a living, including 1.6 million Yemenis, according to the UN.