The UN on Wednesday described growing international anger at Yemen’s Iran-backed Houthi rebels for again stalling repairs to a decaying oil tanker that could cause an environmental disaster by spilling its million-barrel load into the Red Sea.
UN spokesman Stephane Dujarric said new Houthi demands over a UN engineering team's assessment mission to the stranded FSO Safer further set back an operation that was originally scheduled for the end of January.
The Houthis, who have since 2014 controlled much of northern Yemen, have delayed several UN efforts to repair the Safer, an oil platform moored off the Red Sea coast, which experts say could rupture soon and release 1.1 million barrels of oil.
The Houthis in recent days made “additional requests focused on logistics and security arrangements”, leaving UN officials unable to say when the mission could be sent, said Mr Dujarric.
"We understand that many member states, including donors to the projects, are extremely concerned by these new delays,” he said.
The UN was working to “finalize mission preparations” but “sometimes the goalposts seem to shift”, added the spokesman.
The UN has repeatedly asked the Houthis to grant it access to repair the vessel and prevent a maritime disaster that experts fear would be four times worse than the 1989 Exxon Valdez spill near Alaska.
“By the grace of God, there has not been a major leak. The more we wait, the chances of a major leak are increasing,” Mr Dujarric said.
“A leak would have devastating ecological, humanitarian and economic consequences, not only for the people of Yemen but for the entire region around the Red Sea.”
Houthi officials approved a mission late last year, but that now looks to be unlikely despite the UN spending $3.35 million on recruiting engineers, leasing a barge and a tugboat and acquiring other gear.
The rebels have said the mission can still proceed, but analysts say the Houthis want the FSO Safer in place to profit from its cargo and future oil sales, and to raise the risks for any seaborne assault by foreign forces.
Yemen's internationally recognised government and some major world figures, including former UK foreign minister Sir Alan Duncan, have urged the UN Security Council to authorise a salvage mission, possibly backed by armed force.
For the first time on Wednesday, Mr Dujarric addressed the prospect of a “Chapter Seven discussion” in the council – referring to the section of the UN Charter dealing with military force – saying a conversation had yet to “evolve”.
Houthi rebels drove Yemen's government from the capital, Sanaa, in 2015. They control much of the areas north and around the Red Sea port of Hodeidah, near where the decaying FSO Safer has been moored for decades.
The 45-year-old vessel has been stranded 8 kilometres south-west of Ras Isa oil terminal, 60km north of the Houthi-held port of Hodeidah, since 2015, when the rebels took control of the area.
A major spill would hurt tourism, fishing and desalination plants across Yemen, Saudi Arabia, Israel, Jordan, Egypt, Sudan, Eritrea and Djibouti, and impede a shipping lane that carries as much as 10 per cent of global trade.