The United Nations declared that the mission to rescue the FSO Safer has begun in order to prevent an oil spill disaster off the coast of Yemen, noting that a big tanker dedicated to cleaning oil has sailed from China on its route to Yemen.

The "Nautica" set sail on Wednesday after receiving standard maintenance at Zhoushan, China, according to the UN Development Program.

The ship, which was purchased by the international tanker company Euronav, is scheduled to arrive in early May and will stop along the way to perform additional technical adjustments, according to a United Nations spokesperson.

"The departure of the Nautica, and its onward journey to the Red Sea, is a significant next step in the complex operation to take on the oil from the Safer," said UNDP chief Achim Steiner, according to the statement.

He called for urgent contributions to fund the operation, the $129 million budget for which still has a gap of $34 million as of April 4. The UN has even launched a crowdfunding page, aiming to raise $500,000.

"We are in a race against time and I urge leaders in government, CEOs of corporations, and any individual in a position to contribute to step forward and support us in keeping this operation, which is fast reaching a critical stage, on track," Steiner said.

"We have the best available technical expertise and political support from all sides," David Gresley, the UN Humanitarian Coordinator for Yemen said. "We just need the final piece of funding this month to ensure success" and prevent "a catastrophe," he added.

The United Nations had launched a fund-raising campaign to finance this operation, anticipating a total cost of $144 million, which includes, in a second phase, replacing Safer with a safer and more sustainable solution.

According to the United Nations, the Safer tanker carries four times the amount of oil that spilled from the Exxon Valdez tanker in 1989, which led to one of the largest environmental disasters in US history.

Last year, the non-governmental environmental organization Greenpeace called on Arab countries to act “before it is too late,” because “the risks posed by Safer are not limited to the people of Yemen and neighboring countries.

The Sanaa government has repeatedly warned of the catastrophic repercussions in the event of the "Safer" oil tank explosion, which "may extend to the Suez Canal."

The Yemeni Armed Forces signed a memorandum of understanding on March 5 that authorizes the UN to transfer around 1.1 million barrels of oil from the ship.

The oil would be moved to a safe vessel that would remain in place. Within 18 months, a new ship would be bought for the Yemeni Armed Forces to replace Safer, ensuring that they would be able to operate a thriving oil export enterprise once the war is over. The Safer vessel would then be towed and sold for scrap. 

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