Israel has accused the United Nations of undercounting aid entering Gaza, saying on Wednesday the U.N. was using a flawed approach meant to conceal its own distribution difficulties, amid growing pressure on Israel to let in more relief supplies.

While Israel says the number of trucks entering Gaza has risen sharply in recent days, the U.N. has given much lower figures, and says it is still far less than the amount required to meet humanitarian needs.

Six months into Israel's ground and air offensive, triggered by the Hamas attack of Oct. 7, most of Gaza's 2.3 million people are homeless, parts of the enclave face famine, civilian infrastructure has been devastated and disease is widespread.

Aid agencies, including U.N. agencies, have urged Israel to do more to let in food and other humanitarian aid, and to facilitate its distribution around the tiny enclave.

While Israel said 419 trucks entered the Gaza Strip on Monday, the main U.N. agency there, UNRWA, said only 223 trucks had come in on that day.

Both COGAT, the Israeli military branch responsible for aid transfers, and U.N. agencies have said the discrepancy in numbers results from different ways of counting.

"The U.N.'s incorrect numbers are a result of their flawed counting method. Rather than counting the actual number of trucks that enter the Gaza Strip, in an attempt to conceal their logistical distribution difficulties, they only count the trucks that they have picked up from the Gazan side of the border," COGAT said in a statement.

On Tuesday, Jens Laerke the spokesperson for the U.N. humanitarian agency OCHA said the Israeli count was for trucks that were only partially filled to comply with its military's screening requirements.

"COGAT counts what they screen and send across the border. We count trucks that arrive in our warehouses," Laerke said.

"Trucks that go in, screened by COGAT, are typically only half full. That is a requirement that they have put in place for screening purposes. When we count the trucks on the other side, when they have been reloaded, they are full," he said.

Other Israeli restrictions mean the trucks often do not move through the border and into warehouses in a single day, further complicating a clear count, Laerke said.

"Egyptian drivers and trucks can never be in the same area at the same time as Palestinian drivers and trucks. That means there is not a smooth handover. First everything has to come in, has to be offloaded, everybody has to go out, before a new set of trucks from inside Gaza with Palestinian plates, with vetted Palestinian drivers, can go in and pick it up," he said.

(Reporting by James MacKenzie in Jerusalem and Gabrielle Tetrault-Farber in Geneva; Writing by Angus McDowall; Editing by Sharon Singleton)