ATLANTA, USA (CNN) – The U.S. government is in discussions with partner countries, including Egypt and Israel, to ensure safe passage for Americans and other citizens from the Gaza Strip, U.S. officials told CNN.

But according to a US source, Egypt wants to use the humanitarian corridor to send food and medical supplies to Gaza, but does not want to open the border in the other direction to receive civilians fleeing the Strip.

US State Department spokesman Matthew Miller said on CNN on Wednesday: “We believe it is important to allow American citizens in Gaza to leave, and that is an issue we are working on.”

“We’re doing it quietly, like many other diplomatic efforts we undertake,” Miller added. “It’s not constructive to talk about it publicly, but we’re doing it. It’s something we’re trying to accomplish.”

As pressure to establish a humanitarian corridor mounts, Americans in Gaza who spoke to CNN expressed fear and frustration over the situation as they are trapped without a safe route out of the area, which has been heavily bombarded by Israeli forces.

They told CNN they didn’t think the US government would be able to help them, and there were reports that the only route to Gaza – through Egypt – had been closed by airstrikes on Tuesday and that Israeli ground forces were threatening to invade.

“We have had discussions with our counterparts in Israel and with our counterparts in Egypt,” National Security Adviser Jake Sullivan said on Tuesday.

Sullivan added, “Without going into the details of safe passage for the public and so on, I would say that’s something the US government is interested in how to implement in practice.”

Neither Sullivan nor Miller provided a timeline for when the safe corridor would be operational.

The U.S. national security adviser spoke with Abbas Kamel, the director of the General Intelligence Service in Egypt, over the past few days, and officials expect U.S. President Joe Biden to speak later with his Egyptian counterpart, Abdel Fattah el-Sisi.

“Our priority is protecting the safety and security of Americans abroad,” Miller said Wednesday. “As the president said yesterday, we don’t want civilians killed anywhere. We want to protect civilians. We want to make sure that civilians are not targeted. We expect Israel to follow the laws of war.