(Reuters) - The United Nations is planning new routes to distribute aid from a U.S.-built pier in Gaza, a spokesperson said, after crowds of needy residents intercepted trucks, causing a halt to deliveries that continued for a third day on Tuesday.

The temporary, floating pier is meant to help ease the humanitarian crisis in Gaza, though aid workers say that only deliveries through land borders can ensure relief on the scale that is needed.

Operations at the pier began on Friday and the U.N. said 10 truckloads of food aid - transported from the pier by U.N. contractors - were received at a World Food Programme (WFP) warehouse in Deir El Balah in Gaza. But on Saturday, only five truckloads made it to the warehouse after 11 others were intercepted.

Distribution was then paused as logistics teams planned new routes and coordination of deliveries in an effort to prevent more aid being intercepted, said Abeer Etefa, a WFP spokesperson in Cairo.

"The missions were planned for today using the new routes to avoid the crowds," she said. "Up until now we haven't heard that they moved."

The pier has been met with hope and scepticism by residents in Gaza.

"The pier should be there when the (Israeli) occupation completely ends. Then, it will be good for us. It will be good to travel, to get things," said one, Abu Nadi al-Haddad, questioning why it was needed now, given the existence of several land crossings.

'WAITING FOR AMERICAN AID'

Another resident, Abu Nasser Abu Khousa, came to the coastal road close to where the pier is located with his four-year-old son and a donkey-drawn cart in the hope of receiving aid.

"We are waiting for the American aid, but we did not get anything," he said, adding that he had lost his home in the war and had been displaced multiple times.

"We will come back tomorrow, God willing, in the hope that we will get some aid, that will help us survive."

The war between Israel and Hamas that broke out last October has caused a deep humanitarian crisis in Gaza, with many of the coastal enclave's 2.3 million residents facing chronic shortages of food and medicines.

Deliveries of international aid have fallen sharply since Israel stepped up military operations in and around the southern city of Rafah on May 7, closing the Rafah border crossing to Egypt's Sinai Peninsula.

Aid offloaded at the floating pier comes by ship from Cyprus, where it is first inspected by Israel. The pier operation is estimated to cost $320 million and involve 1,000 U.S. service personnel.

U.S. Central Command said late on Monday that more than 569 metric tonnes of relief donated by the U.S., Britain, the United Arab Emirates and the European Union had so far been delivered to the pier.

It was unclear how much aid has been waiting at the pier since distribution by the U.N. into Gaza was suspended on Saturday.

(Reporting by Aidan Lewis and Michelle Nicholls; Editing by Gareth Jones)