Gaza-bound aid supplies were being loaded onto a vessel in Greek Cyprus, which will be the first cargo to be transported through the U.S. offshore jetty, as Israel continues its invasion of the Rafah area.

Containers were being stacked on the U.S.-flagged Sagamore, docked at the port of Larnaca, on Wednesday. Some containers going to the ship were labeled as aid from the United Arab Emirates.

"We are completing the loading of aid onto a U.S. vessel now in Larnaca, and once the platform is in place, this part of the process (shipment) can commence," said Konstantinos Letymbiotis, a Greek-Cyprus government spokesperson.

It was unclear when the vessel would depart. The Pentagon said on Tuesday that it had completed construction of the pier and was hoping to move it off the coast of Gaza later this week.

A senior Biden administration official, speaking to reporters on condition of anonymity, said last month that aid coming off the U.S. pier will need to pass through Israeli checkpoints on land. That is despite the aid having already been inspected by Israel in Cyprus prior to being shipped to Gaza.

The prospect of checkpoints raises questions about possible delays even after aid reaches shore. The United Nations has long complained of obstacles to getting aid in and distributing it throughout Gaza.

The United Nations is in talks with the U.S. about the distribution of aid once it comes off the pier. A U.N. spokesperson had no update on Wednesday when asked about the status of the talks.

"We have determined a number of parameters under which the U.N. family is able and in a position to receive and distribute the goods," the U.N. humanitarian and reconstruction coordinator for Gaza, Sigrid Kaag, said last month. "But there are also a number of international NGOs that are considering participating in the distribution of goods that come via the maritime corridor."

Kaag said some of the parameters being discussed included effective deconfliction, the ability of the U.N. to distribute aid all over Gaza and for the U.N. to ensure its neutrality by remaining at an appropriate distance from the Israeli military, which will provide security and logistics support for the pier.

"We're hopeful that we're getting there," she said of the talks two weeks ago.

The United Nations has also been adamant that maritime access was no substitute for land deliveries, which needed to remain the focus of aid operations in Gaza.

Israel's attacks against Gaza have devastated the tiny Gaza Strip, where aid agencies warn its 2.3 million people are facing imminent famine.

Greek Cyprus opened a sea corridor in March to ship aid directly to Gaza, where deliveries via land have been severely disrupted by border closures and Israel's military operations.

U.S.-based charity World Food Kitchen used the route twice before seven of its workers were killed in an Israeli air strike on April 1.