The U.S. government is considering greenlighting the sale of up to 50 F-15 fighter jets and munitions to Israel in a deal expected to be worth at least $18 billion, despite expressing concern over the high civilian death toll in Gaza, several media reports said Monday.

The sale package includes up to 50 new F-15 fighter jets, 30 AIM-120 advanced medium-range air-to-air missiles and a number of Joint Direct Attack Munition kits that turn dumb bombs into precision-guided weapons, Politico reported, citing a congressional aide and a person familiar with the discussions.

The sale needs U.S. government approval and it would likely take years for the weapons to arrive in Israel. However, the administration has already informally notified the relevant congressional committees, the report said, citing congressional sources, which shows they are ready to move forward with the sale.

The administration is also expected to notify Congress soon about the new sale of precision-guided munitions kits to Israel, according to CNN.

Asked about the reports, a State Department spokesperson told Anadolu Agency (AA) that they are not able to confirm potential or pending U.S. arms transfers before they are formally notified to Congress.

"In accordance with the Arms Export Control Act, fulfilling an authorization from one notification to Congress can result in dozens of individual FMS cases across the decadeslong lifecycle of the Congressional Notification," the spokesperson said.

"As a matter of practicality, major procurements, like Israel's F-35 program for example, are often broken out into several cases over many years," the spokesperson added.

The sale of 25 F-15s from Boeing Co. to Israel has been under review since the United States received the formal request in January 2023, one of the sources told Reuters, long before Israel's nearly six-month military campaign in Gaza. This sale would boost that number to as many as 50 F-15s.

Speeding up the delivery of the aircraft was among the top asks by Israeli Defense Minister Yoav Gallant, who visited Washington last week and held talks with U.S. officials, including National Security Advisor Jake Sullivan and Secretary of Defense Lloyd Austin, a second source told Reuters.

The U.S. President Joe Biden faces pressure from foreign partners, human rights groups and some of his fellow Democrats in Congress to impose conditions on arms transfers to rein in Israel’s offensive on Gaza where health officials say more than 32,000 Palestinians have been killed, many of them civilians.

The reports of the new weapons sale to Israel come over the demands of a growing number of Democrats who have urged the U.S. president to condition any additional provision of arms to Israel on its military conduct and remove obstructions to the provision of international humanitarian assistance.

Last month, a half-dozen Democratic senators sent a letter to Biden urging him to halt arms sales to Israel because it is currently in violation of a 1961 law that prohibits arms sales to nations that obstruct the delivery of American aid.

"The United States should not provide military assistance to any country that interferes with U.S. humanitarian assistance," Senators Bernie Sanders, Chris Van Hollen, Jeff Merkley, Mazie Hirono, Peter Welch, Tina Smith, Elizabeth Warren and Ben Ray Lujan wrote.

"Federal law is clear, and, given the urgency of the crisis in Gaza and the repeated refusal of Prime Minister (Benjamin) Netanyahu to address U.S. concerns on this issue, immediate action is necessary to secure a change in policy by his government," they added.

A Feb. 8 memorandum signed by Biden requires countries that receive U.S. military assistance to give Washington "credible and reliable written assurances" that the arms will be used in compliance with "international human rights law and international humanitarian law."

Israel submitted written assurances to the State Department last month, but human rights groups say Israel's assurances to the U.S. government are not credible, urging the government to suspend arms transfers to Israel.

Human Rights Watch and Oxfam submitted a report to the Biden administration last month listing a wide range of Israeli violations of international humanitarian law since Oct. 7, including the use of U.S.-supplied white phosphorus in military operations in Lebanon and Gaza, disproportionate strikes on or near several major hospitals and an ambulance, and the systematic blocking of U.S.-funded assistance.

One U.S. official told Reuters the earliest the aircraft would be delivered is 2029, and that is if the formal notification were sent to Congress and it was finalized immediately.

House of Representatives Foreign Affairs Committee Chairperson Michael McCaul gave the green light for the F-15 sale on Jan. 30, a committee aide said, when the relevant congressional offices responsible for approving major arms transfers were notified.

"Administration-Congressional deliberations on the F-15 case have already occurred," the second source familiar with the matter said, but added that some of the four offices required to sign off on any arms transfers had yet to do so.

U.S. law requires Congress to be notified of major foreign military sales agreements and allows it to block such sales by passing a resolution of disapproval over human rights violations or other concerns, although no such resolution has ever passed and survived a presidential veto.

An informal review process allows the Democratic and Republican leaders of foreign affairs committees to vet such agreements before a formal notification to Congress.

Planes, munitions, support

The Israel package includes 50 F-15 aircraft, and support services, training, maintenance, sustainment and many years of contractor support during the jets' lifecycle, which could typically go for up to two decades, sources said.

One source told Reuters the Biden administration had expressed support to Israel for its F-15 request.

Washington has publicly expressed concern about Israel's anticipated military offensive in Rafah, the southernmost city of the Gaza Strip where many Palestinians have taken shelter after being displaced due to Israel's Gaza assault.

Washington gives $3.8 billion in annual military assistance to its longtime ally Israel, and the administration has so far resisted calls to condition any arms transfers even though senior U.S. officials have criticized Israel over the high civilian death toll.

This sale is separate from the $14 billion in aid for Israel that Biden has asked Congress to approve as part of a sweeping $95 billion national security supplemental spending package that also includes aid for Ukraine and Taiwan.

The State Department did not immediately respond to a request for comment.

Gallant discussed Israel's weapons needs during a visit to Washington last week. He told reporters he had stressed to senior U.S. officials the importance of maintaining Israel’s qualitative military edge in the region, including its air capabilities.

The Israeli Embassy in Washington did not immediately respond to a Reuters request for comment. Boeing did not immediately respond to a request for comment.

Israel has waged a deadly military offensive on the Gaza Strip since an Oct. 7 cross-border attack by the Palestinian group Hamas, which Israeli officials say killed some 1,200 people.

At least 32,845 Palestinians have since been killed and nearly 75,400 others injured amid mass destruction and shortages of necessities. Israel has imposed a crippling blockade on the Gaza Strip, leaving its population, particularly residents of northern Gaza, on the verge of starvation.

The Israeli war has pushed 85% of Gaza’s population into internal displacement amid acute shortages of food, clean water and medicine, while 60% of the enclave's infrastructure has been damaged or destroyed, according to the U.N.