According to sources familiar with the matter, including a US official and a former US official, the request is being made even as concerns grow about the use of US weapons in a war that has killed thousands of civilians in the Palestinian enclave since Israel responded to an attack on October 7 by Hamas.
The potential sale, worth more than US$500 million, is not part of President Joe Biden's US$110.5 billion supplemental request that includes funding for Ukraine and Israel.
It is under informal review by the Senate Foreign Relations and House of Representatives Foreign Affairs committees, which allows members the privilege to stall the sale or have informal discussions with the administration about concerns.
The US State Department is pushing the congressional committees to quickly approve the transaction, said a US official and Josh Paul, a former State Department official.
The administration is also weighing using Arms Export Control Act emergency authorities to allow a portion of the ammunition, 13,000 of the 45,000 shells, to bypass the committee and review period, two US officials said, although a final decision was yet to be made.
Online images of the war show that Israel regularly deploys Merkava tanks in its Gaza offensive and on its southern border with Lebanon, where skirmishes have erupted since October 7.
The tanks are also linked to incidents that involved the death of journalists.
On Thursday, a Reuters investigation revealed that an Israeli tank crew killed Reuters journalist Issam Abdallah and wounded six reporters by firing two shells in quick succession from Israel while the journalists were filming cross-border shelling.
Israel has sharply increased strikes on the Gaza Strip since a seven-day-long truce ended a week ago, pounding the length of the Palestinian enclave and killing hundreds in a new, expanded phase of the war that Washington said veered from Israeli promises to do more to protect civilians.
Gaza's health ministry said the death toll from Israel's campaign in Gaza had risen to 17,487.