The US Senate has blocked legislation that would have halted the sale of some US weapons to Israel, which had been introduced out of concern about the human rights catastrophe faced by Palestinians in Gaza.

Senator Bernie Sanders had introduced what are called joint resolutions of disapproval, seeking to block the Biden administration’s recent sale of $20bn in US weapons to Israel.

Moves to advance three resolutions all failed, garnering only about 20 votes out of the chamber’s 100 members, with most Democrats joining all Republicans against the measures.

The Senate was to vote later on Wednesday on two other resolutions that would stop shipments of mortar rounds and a GPS guidance system for bombs.

Sanders introduced the measures in September as Israel continued its assault on Gaza – which has killed at least 43,000 people.

“Prime Minister Benjamin Netanyahu’s extremist government has not simply waged war against Hamas – it has waged war against Palestinians,” Sanders said a press conference held on Tuesday ahead of the vote.

“Much of what’s been happening there has been done with US weapons and American taxpayer support,” Sanders continued, adding that the US has provided more than $18bn in military aid to Israel and delivered more than 50,000 tons of armaments and military equipment.

“The United States of America is complicit in these atrocities. This complicity must end.”

The Sanders-led effort to stop the flow of arms to Israel came after the country failed to meet the US-imposed deadline of 12 November to increase humanitarian aid and allow at least 350 trucks into Gaza a day. Despite Israel’s failure, the US took no action.

Under US law, military assistance must not be given to foreign security forces that have committed human rights violations. However, the Biden administration has largely refused to stop the transfer of weapons to Israel, despite persistent accusations of war crimes from human rights experts.

Senator Elizabeth Warren had vocalized support for the resolutions and condemned the Biden administration for not taking action against Israel for failing to meet its deadline for aid into Gaza.

“The failure by the Biden administration to follow US law and to suspend arms shipments is a grave mistake that undermines American credibility worldwide,” Warren said in a statement. “If this administration will not act, Congress must step up to enforce US law and hold the Netanyahu government accountable through a joint resolution of disapproval.”

It is not the first time Sanders has led such an effort, and this one was not expected to pass. But backers hoped significant support in the Senate would encourage Israel’s government and Joe Biden’s administration to do more to protect civilians in Gaza.

The Democratic senator Jeff Merkley, who co-sponsored the resolutions, said he opposed the transfer of offensive weapons used for bombing, which has “produced massive deaths, massive injuries, massive destruction”.

“I stand before you today as someone who has spent a lifetime advocating for Israel’s economic success and for their security in a very difficult part of the world,” Merkley said, adding: “But the Netanyahu government has taken policies that are out of sync with American values.”

More than 65% of housing, schools and healthcare facilities have been destroyed by Israeli forces, according to UN data. All 12 universities in the territory have been damaged or destroyed, according to Wafa, the Palestinian news agency. The UN also estimates that about 90% of Gaza’s 2.3 million Palestinians have been displaced. Humanitarian groups on the ground have reported malnutrition and starvation and global food security experts say famine in northern Gaza is imminent.

A spokesperson from Oxfam, a British non-governmental organization that has been providing aid to the displaced in the region, said: “The Senate must vote to finally end arms transfers to Israel, as we see the crisis continue to escalate with warnings of imminent famine and entire communities being permanently erased in North Gaza governorate.

“Israel is blocking humanitarian aid, and is meanwhile using US weapons in attacks that have killed thousands of children, aid workers, and journalists, destroyed schools, hospitals, vital infrastructure for clean water and more, and displaced hundreds of thousands of Palestinians in Gaza, where there is nowhere safe.”

It has been more than a year since Hamas’s surprise and deadly attacks last 7 October. Negotiations for a ceasefire and hostage deal between Israel and Hamas have repeatedly failed.

AFP and Reuters contributed reporting