Before the conflict, about 500 trucks a day were crossing into Gaza, but in recent days, an average of only 12 trucks a day have entered.
The United States is negotiating with Israel, Egypt and the United Nations to try and create a sustained delivery mechanism to get aid into Gaza.
Deliveries of aid through Rafah began on Saturday after wrangling over procedures for inspecting the aid and bombardments on the Gaza side of the border had left relief materials stranded in Egypt.
Distribution of those supplies began on Sunday, but aid officials are still warning of a humanitarian disaster as supplies of food, water, and fuel run low.
Israel imposed a total blockade and launched air strikes on Gaza in response to a deadly attack on Israeli soil by Palestinian group Hamas on Oct. 7.
Israel's bombardment and siege of Gaza is in retaliation for a devastating Hamas incursion into Israel on Oct. 7 during which 1,400 people were killed and hostages were taken.
After nine hours of negotiations, US Secretary of State Antony Blinken said early on Tuesday he had agreed with Israel "to develop a plan" to get aid into Gaza.
The reports of the crossing reopening come as relief groups continue to warn of a deepening humanitarian crisis in Gaza.
Egypt has long restricted the flow of Gazans on to its territory, even during the fiercest conflicts.
The terminal, the only crossing point between Egypt and the Gaza Strip, has been under Hamas' control since its violent takeover of the Gaza Strip in 2007.