(NewsNation) — Israeli Prime Minister Benjamin Netanyahu has ordered the Israeli army to develop an evacuation plan ahead of an attack on Rafah — Gaza’s southernmost city — which is widely considered the last Hamas stronghold.

But given the extent to which Rafah has grown in the months since the Israel-Hamas war began, evacuating more than 1 million people would involve a massive undertaking.

The White House is again calling for the creation of a safety plan for the nearly 1.5 million Palestinian civilians living in Rafah. National security spokesman John Kirby said Tuesday that provisions need to be made for the civilians’ well-being ahead of a possible attack.

The U.S. concerns come after Israeli airstrikes killed nearly 100 people in Rafah earlier this week when several parts of the city were shelled.

Kirby said Monday that President Joe Biden is confident that Israel has heard U.S. concerns “loud and clear.” On Tuesday, Kirby again called for civilians’ safety to be made a top priority.

“Any credible (safety) plan would have to take into account (civilians) physical movement, safe movement, as well as a proper substance for them — food, water, medicine, access to healthcare — and be able to stay together as family units,” Kirby said.

Where is Rafah?

Rafah is located in North Sinai and is the lone border crossing between Gaza and Egypt and remains the only way in and out of Gaza.

The city falls along an 8-mile fence that divides Gaza and the Sinai desert and is currently the only way in and out of Gaza.

Who controls Rafah?

Rafah fell under Egyptian control in the 1948 Arab-Israel war and was captured by Israel in the 1967 war. After Israel withdrew troops there in 2005, Israel and Egypt have maintained control of their respective borders with the city and Israel has restricted sea and air travel, National Public Radio reported.

The blockade was tightened in early October following the attack on Israel when Hamas militants killed 1,400 people and took an estimated 240 hostages.

Hamas took over the city in 2007 when control of the Rafah crossing was taken over by the European Union, which has worked closely with Egyptian officials. About 450,000 passengers used the crossing between 2005-07, according to CNN, with the crossing seeing about 1,500 people were day using the crossing.

In non-war times, Rafah is used by Palestinians needing to cross into Egypt for medical care and for personal reasons.

However, since the border has become more tightly controlled, moving in and out of Gaza — including by those who have tried to provide humanitarian assistance — has become much more difficult, NPR reported. The strict border closures will make civilians’ attempts to move even farther south than they already have to avoid the warfare nearly impossible, officials said.

How many people live there?

The city normally has a population of around 300,000. However, since the war began in early October, Rafah’s population has swelled to nearly 1.5 million, many of whom are living in tents. Israel has instructed Palestinians to take shelter in Rafah because it is safe.

Many of those living in Rafah among Hamas militants are civilians, which accounts for more than half of the Gaza Strip’s population. Many of those who have arrived there have done so to escape fighting. Since arriving, many of those who have taken refuge in Rafah have not received any humanitarian aid due to the closure of Gaza’s borders, the Wall Street Journal reported.

Calls for Evacuation

Amid concerns that a ground attack could be catastrophic given the estimated 600,000 children currently living in Rafah, the U.S. and European countries are calling for the city to be evacuated along with Israel’s Prime Minister.

A ground attack on Rafah has been predicted for months after Netanyahu said vowed Israel’s attacks will continue until the country has claimed “total victory”, which would include Hamas’ destruction.

Last week, Netanyahu again called for civilians to be evacuated as a means to achieving victory.

“It is impossible to achieve the goal of the war of eliminating Hamas by leaving four Hamas battalions in Rafah,” Netanyahu’s office said, according to Vox.