Israel says it is reopening the Kerem Shalom crossing with southern Gaza for aid deliveries, four days after it was closed because of Hamas rocket fire.
Lorries from Egypt with food, water and medicine have arrived at the crossing, according to the Israeli military.
The UN had expressed alarm on Tuesday over what it called Israel`s "choking off" of Gaza`s two main aid arteries.
It came after Israeli troops took full control of the Palestinian side of the Rafah crossing with Egypt.
Overnight, there were fresh Israeli air strikes in the nearby city of Rafah, where the Israeli military says it began a limited operation on Monday.
A senior US official also confirmed that a shipment of US weapons to Israel had been paused last week over concerns that Israeli forces were about to launch a major offensive on Rafah city.
The shipment included 2,000lb bombs, which could be devastating if used in such a densely populated place.
Seven months into its war with Hamas in Gaza, Israel has said that victory is impossible without taking Rafah.
But with more than a million displaced Palestinians taking refuge there from the fighting elsewhere, the UN and Western powers have warned that an all-out assault could have devastating humanitarian consequences.
Kerem Shalom is the key entry point for aid into Gaza, but Israel closed it on Sunday after four Israeli soldiers were killed by rockets launched by Hamas from the area of the Rafah crossing, according to the Israeli military.
Another six projectiles were fired at Kerem Shalom from the Rafah area on Tuesday, but no casualties were reported.
The second attack happened hours after Israeli tanks rolled into the Palestinian side of the Rafah crossing as part of what the military called a "precise" operation to "eliminate Hamas terrorists and dismantle Hamas terrorist infrastructure within specific areas of eastern Rafah".
UN Secretary General António Guterres said he was "disturbed and distressed" by the Israeli military activity.
He also warned that the closure of both Rafah and Kerem Shalom crossings was "especially damaging to an already dire humanitarian situation" and demanded that they be reopened immediately.
