The U.S. military-built pier to carry humanitarian aid to Gaza will be dismantled and brought home, ending a mission that has been fraught with repeated weather and security problems that limited how much food and other supplies could get to starving Palestinians.

Vice-Admiral Brad Cooper, deputy commander at U.S. Central Command, told reporters in a Pentagon briefing on Wednesday that the pier achieved its intended effect in what he called an "unprecedented operation." 

As the U.S. military steps away from the sea route for humanitarian aid, questions swirl about Israel's new plan to use the port at Ashdod as a substitute. There are few details on how it will work and lingering concerns about whether aid groups will have enough viable land crossings to get assistance into the territory besieged by war between Israel and Hamas. But Cooper said the Ashdod corridor will be more sustainable.

Critics called the pier a $230-million US boondoggle that failed to bring in the level of aid needed to stem a looming famine.

The U.S. military, however, has maintained that it served as the best hope, as aid only trickled in during a critical time of near-famine in Gaza and that it got close to 20 million pounds (nine million kilograms) of desperately needed supplies to the Palestinians.

WATCH | Pier built by U.S. in Gaza receives 1st aid shipment:

Temporary pier built by U.S. in Gaza receives 1st aid shipment

A new temporary pier built by the U.S. is helping bring desperately needed aid to Gaza. The first shipment of humanitarian aid has already started rolling into the besieged enclave, but UN officials say it's no replacement for deliveries by land.

U.S. President Joe Biden, who announced the building of the pier during his State of the Union speech in March, expressed disappointment that it didn't do as well as hoped.

"I've been disappointed that some of the things that I put forward have not succeeded as well — like the port we attached from Cyprus," Biden, a Democrat, said during a news conference last week. "I was hopeful that would be more successful."

Operated for fewer than 25 days

Planned as a temporary fix to get aid to starving Palestinians, the project was panned from the start by aid groups that condemned it as a waste of time and money. While U.S. defence officials acknowledged that the weather was worse than expected and limited the days the pier could operate, they also expressed frustration with humanitarian groups for being unable and unwilling to distribute the aid that got through the system, only to have it pile up onshore.

A critical element that neither the aid groups nor the U.S. military could control, however, was the Israeli defence forces whose military operation into Gaza put humanitarian workers in persistent danger and in a number of cases cost them their lives.

As a result, the pier operated for fewer than 25 days after its installation on May 16, and aid agencies used it only about half that time due to security concerns.

Stuck in the middle were the more than 1,000 U.S. soldiers and sailors who largely lived on boats off the Gaza shore and struggled to keep the pier working but spent many days repairing it or detaching it, moving it and reinstalling it due to the bad weather.

The tensions played out until the final moments, as senior Biden administration officials signalled the end of the pier project days ago, but U.S. Central Command balked, holding out hope the military could reinstall it one last time to move any final pallets of aid ashore. 

Most would agree that use of the maritime route and what is known as the Army's Joint Logistics Over the Shore capability, or JLOTS, fell short of early expectations. Even at the start, officials warned of challenges because the sea is shallow, the weather is unpredictable and it was an active war zone. 

The U.S. also had to train Israeli troops and others on how to anchor the pier to the shore because no U.S. troops could step foot on Gaza soil, a condition Biden has had since the beginning of the Hamas-Israel conflict in October.

WATCH | Rachael Cummings of Save the Children on hunger in Gaza:

Rachael Cummings of Save the Children on hunger in Gaza

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However, enough aid to feed 450,000 people for a month flowed through the pier, according to the United States Agency for International Development (USAID), which co-ordinated with the United Nations and others to get supplies to people in need.

As important, humanitarian leaders say, the pier operation laid the groundwork for a co-ordination system with the Israeli government and military that they can expand on.

Other aid groups, however, slammed the U.S. military pier as a distraction, saying the U.S. should have instead pressured Israel to open more land crossings and allow the aid to flow more quickly and efficiently through them.

WATCH | Medical care becoming impossible in Gaza:

Medical care becoming impossible in Gaza

WARNING: Video contains distressing images | As Israel's war in Gaza drags on, it’s become almost impossible for seriously sick or wounded Palestinians to get the medical care they need, especially because leaving the country is no longer a viable option.

Everyone has agreed all along that land crossings are the most productive way to get aid into Gaza, but the Israeli military has routinely blocked routes and slowed deliveries due to inspections. Aid groups also were terrorized by attacks, from Hamas, gunmen who stripped convoys of supplies and the Israeli military. More than 278 workers have been killed in the conflict, said Samantha Power, administrator of USAID.

Weather forced troops to detach the pier from the shore two more times and move it to Ashdod. It was detached for the final time on June 28, and poor weather prevented the U.S. from reinstalling it.

Aid groups struggled to distribute the supplies from the pier into Gaza, and their efforts came to an abrupt halt after a June 8 Israeli military raid that rescued four hostages but killed hundreds of Palestinians.