Some of Israel's actions in its war against Hamas, like cutting off food and water for Gaza, could "harden Palestinian attitudes for generations" and weaken international support for Israel, former U.S. President Barack Obama said on Monday.

In rare comments on an active foreign policy crisis, Obama said any Israeli military strategy that ignores the human costs of the war "could ultimately backfire."

"The Israeli government's decision to cut off food, water and electricity to a captive civilian population (in Gaza) threatens not only to worsen a growing humanitarian crisis; it could further harden Palestinian attitudes for generations, erode global support for Israel, play into the hands of Israel's enemies, and undermine long-term efforts to achieve peace and stability in the region," Obama said.

Israel has heavily bombarded Gaza with air strikes since Hamas' Oct. 7 assault on Israel left over 1,400 people dead. Israel's air strikes have killed more than 5,000 Palestinians, Gaza officials say.

Obama condemned Hamas' attack and reiterated his support for Israel's right to defend itself, while cautioning about risks to civilians in such wars.

It was not clear whether Obama had coordinated his statement with U.S. President Joe Biden, who served as his vice president for eight years.

During his presidency, Obama often backed Israel's right to self-defense at the start of conflicts with Palestinian Islamist group Hamas in Gaza, but quickly called for Israeli restraint once Palestinian casualties mounted from airstrikes.

Gaza, a 45 km-long (25-mile) strip of land that is home to 2.3 million people, has been ruled politically since 2007 by Hamas, an Iran-backed Islamist group, but faces a blockade from Israel.

The Obama administration sought, but ultimately failed to broker, a peace deal in negotiations between Israel and the Palestinians.

Since taking office in early 2021, Biden has not tried to resume long-stalled talks, saying that leaders on both sides were too intransigent and the climate was not right.

Obama and Israeli Prime Minister Benjamin Netanyahu had a testy relationship when Obama was in office, including when Obama's administration was negotiating a nuclear deal with Iran.

Biden, as Obama's vice president, often acted as a mediator between the two men.

In his statement on Monday, Obama acknowledged that the U.S. had itself "fallen short of our higher values when engaged in war," especially after the Sept. 11, 2001 attacks.