President Joe Biden ordered the structure to be built two months ago.

Pentagon (US Department of Defense) spokeswoman Sabrina Singh told reporters the project will cost at least $320 million, which includes transporting the equipment and pier sections from the US to the Gaza coast, as well as construction and running costs.

The floating pier is intended to help deliver food and other basic supplies that have been unable to reach the enclave, particularly since Israel imposed military control of the Rafah border crossing between Gaza and Egypt.

The installation of the pier, which is now anchored just off the beach, was delayed by almost two weeks because of bad weather and high seas.

The sea conditions made it "too dangerous" for US and Israeli troops to secure the causeway to the shore.

According to the Associated Press, the aid will be unloaded at a port facility built by the Israelis southwest of Gaza City and then distributed by aid groups.

US troops will not be entering Gaza, US officials said.

Aid groups will collect the supplies – which are being pre-positioned in Cyprus – for distribution on land, with the UN working with the US Agency for International Development to set up a logistics hub on the beach.

Heavy fighting between Israeli troops and Palestinian militants around Rafah has displaced an estimated 600,000 people – a quarter of Gaza's population, according to UN officials – with more than 100,000 fleeing their homes in northern parts of Gaza.

The US administration said the fighting in Gaza was not currently threatening the new aid staging area offshore, but made clear that security conditions would be "closely monitored".

The site has already come under mortar fire during its construction.

"Protecting the US forces supporting this effort is a top priority… Over the past several weeks, the US and Israel have developed an integrated security plan to protect all personnel working on the site," said US Navy Vice Admiral Brad Cooper.

US troops anchored the pier on Tuesday morning, US Central Command said in a statement, stressing that no US military personnel entered the Gaza Strip.

"The UN will receive the aid and then coordinate its distribution in Gaza," the statement said, without specifying which UN agency would be involved in the operation.

Aid agencies say they are running out of food in southern Gaza and that fuel is also becoming scarce, forcing hospitals to cancel operations and aid trucks to halt deliveries.

See Also: Netanyahu acusa Egito de "fazer refém" a população de Gaza (Portuguese version)