"As you and your administration work with Israel and international partners to secure the release of hostages and respond to the terror attack on Israel, we join you in your urgent call for humanitarian assistance for Palestinian civilians in Gaza," said the letter, published on Monday.
"We encourage you to work with international partners to achieve expeditious implementation of a plan for sustained humanitarian aid in Gaza."
The letter was signed by 13 Senate Democrats: Sens. Ed Markey (D-MA), Tammy Baldwin (D-WI), Tim Kaine (D-VA), Chris Van Hollen (D-MD), Dick Durbin (D-IL), Brian Schatz (D-HI), Michael Bennet (D-CO), Martin Heinrich (D-NM), Jeff Merkley (D-OR), Peter Welch (D-VT), Elizabeth Warren (D-MA), Tammy Duckworth (D-IL) and Jeanne Shaheen (D-NH).
The lawmakers said in the letter that a heightened and prolonged suffering in Gaza is not only intolerable for the Palestinian civilians but is also expected to negatively impact the security of Israeli civilians.
The suffering in Gaza has the potential to exacerbate existing tensions and erode regional alliances, the letter said.
"Professional militaries have a dual responsibility throughout their campaigns to minimize civilian casualties during tactical operations and to sustain living conditions for civilians," the letter added.
The lawmakers emphasize the significant humanitarian crisis in Gaza, with 1.6 million Palestinians internally displaced - half in makeshift UN shelters - and urged the Biden administration to prompt Israel to collaborate with international relief agencies regarding non-combatants in Gaza.
"This humanitarian crisis will precipitate a significant and preventable loss of human life if not addressed immediately. More than half of Gaza’s hospitals have shut down, desalination plants are struggling to remain operational and the last operative flour mill has been shut down due to a lack of fuel," the letter said.
On October 7, Palestinian group Hamas launched a surprise large-scale rocket attack against Israel from the Gaza Strip and breached the border, killing and abducting people in neighboring Israeli communities. Israel launched retaliatory strikes and ordered a complete blockade of the Gaza Strip, cutting off supplies of water, food, and fuel.
On October 27, Israel launched a large-scale ground incursion inside the Gaza Strip with the declared goal of eliminating Hamas fighters and rescuing the hostages. The conflict has resulted in the deaths of around 1,400 people in Israel and over 11,000 in the Gaza Strip.