WASHINGTON (AP) — More of President Joe Biden's top Senate allies are demanding that the U.S. act directly to ease Palestinian civilian suffering in Gaza and are joining calls to cut military aid if Israeli Prime Minister Benjamin Netanyahu refuses to change course.

What had been dissent from independent Sen. Bernie Sanders and a small group of progressive Democrats has swelled in response to the soaring death toll in Gaza. Now even Biden's closest confidant in Congress, Chris Coons, says it is time to get tougher with Netanyahu's government on how it conducts the war.

Israel continues to enjoy bipartisan support in Congress, and the prospect of military aid being reduced is uncertain despite the clout that these more mainstream Democrats wield. But tensions could be evident Thursday as Biden speaks to Congress about the conflict in his State of the Union address.

The war in Gaza isn't the only Mideast issue creating dissent within the party. Some Democrats are pursuing legislation to compel the administration to seek Congress' permission to continue military strikes against the Houthis in Yemen, setting up a possible showdown over the authority to wage war. The Houthis are attacking shipping in the Red Sea in what they say is a show of support for Palestinians during the nearly five-month war in Gaza.

Still, the Senate Foreign Relations Committee and the Democratic caucus as a whole have largely held off on taking action on the U.S. role in the Middle East conflicts. That's despite growing concern — and rising political opposition nationally, especially among Muslim and Arab American voters — over the Biden administration's support for Israel's war in Gaza, and over Netanyahu's perceived shrugging off of U.S. demands to do more to spare Palestinian civilians and to allow in more aid.

Congressional Democrats are reluctant to be seen as challenging the Democratic president's handling of the conflict, mindful that criticism could further weaken Biden in his uphill reelection campaign against former President Donald Trump.

The killings of more than 100 Palestinians last week during a rare delivery of food helped spur more Biden allies in the Senate to speak out. Israel says its forces fired warning shots amid the chaos of the aid delivery. Witnesses and medical workers told The Associated Press many of the victims were shot when Israeli forces fired into crowds of hungry people.

In the last few days alone, Coons, a senator from Biden's home state of Delaware, called for the U.S. to cut military aid to Israel if Netanyahu goes ahead with a threatened offensive on the southern city of Rafah without significant provisions to protect the more than 1 million civilians sheltering there. Sen. Jack Reed, head of the Senate Armed Services Committee, appealed to Biden to deploy the U.S. Navy to get humanitarian aid to Gaza. Biden ally Sen. Tim Kaine challenged the U.S. strikes on the Houthis as unlikely to stop the Red Sea attacks. And the most senior Democrat in the Senate called for Israel to "change course."

"Israel needs to understand that the casualties they've inflicted on the people of Gaza — the devastation they have caused — cannot continue," Patty Murray of Washington, the senate pro tempore, said in a blistering speech on the chamber floor. "It is not in line with American interests, nor does it make Israel safer."

Continuing U.S. military support for Israel at current levels "becomes untenable when Israel demonstrates they are unwilling to listen to us," Coons told cable networks after the killings during the failed aid distribution.

The National Security Council pointed to Biden's own warnings about the looming Rafah offensive and support for a possible sea route to deliver aid. It did not answer questions about whether the administration has altered its opposition to cutting military aid to Israel or to seeking Congress' permission for its strikes on the Houthis.

Lawmakers have sent at least a half-dozen letters to the administration calling for changes in the conduct of the war since the start of the year. The administration said this week it is actively exploring one possibility, pushed by Reed, to open a sea route for humanitarian aid. The U.S. began air drops to Gaza civilians last week, getting around Israeli restrictions blocking much of the aid delivery by land.

Biden's allies in Congress are trying to drive home the message that Netanyahu's conduct of the war is not in U.S. interests, Sen. Elizabeth Warren, a Massachusetts Democrat, said. Biden and top aides have appealed privately and publicly to Israel for more precision in airstrikes and drone attacks, which have been killing whole families in crowded neighborhoods. Netanyahu also has publicly ruled out the U.S. goal of eventual Palestinian statehood.

"The conversations between senators and the White House are vigorous and frank" regarding the war and Netanyahu, Warren told the AP. "We would not be serving our president to do otherwise."

The Senate Foreign Relations Committee has not marked up legislation related to the region since the war began. And only this past week did the panel hold hearings on the growing Middle East conflicts. Two congressional aides, who spoke to The Associated Press on the condition of anonymity to discuss private meetings, said the chairman, Democratic Sen. Ben Cardin of Maryland, told the committee late last year that no legislation related to the Middle East would move until the war in Gaza is over.

Another congressional aide familiar with the discussions said that in the aftermath of the Hamas attack on Oct. 7 that set off the war, Cardin urged caution on taking any immediate legislative action that would negatively affect the Israeli effort on the ground.

In a statement to the AP, Eric Harris, a spokesperson for the committee, did not directly respond to a question about the lack of legislative action but said the "committee continues to be actively engaged in conducting oversight on Middle East policy, including the ongoing conflict in Gaza, the humanitarian crisis, and efforts to free hostages abducted by Hamas — including American hostages."

The committee cited classified bipartisan briefings it had held, meetings with heads of state and other influential figures, and other key policy advocacy by Cardin, including his leadership in getting Jacob Lew confirmed as U.S. ambassador to Israel.

Meanwhile, on the other side of the Capitol, the House Foreign Affairs Committee has sent over bipartisan bills on the Middle East, including many that would target Iranian officials over Iran's support to Hamas, the Houthis and other armed groups that have stepped up attacks on U.S. and other targets.

Back on the Senate side, notably, it was a subcommittee of the Foreign Relations Committee, rather than the full committee, that summoned two senior Biden administration officials to answer questions about the strikes to try to quell Houthi attacks on international shipping routes.

Sen. Chris Murphy, a Connecticut Democrat, who led the session, said later he was working to gather support from other senators for legislation to compel the administration to seek congressional approval to continue the strikes, in line with his reading of the War Powers Act.

Kaine, a Virginia Democrat, suggested only an end to the fighting in Gaza was likely to calm the region.

"U.S. involvement in another war in the Middle East would reflect that we've learned virtually nothing over the last 25 years.," Kaine said of the U.S. strikes targeting Houthis. "This is the kind of a thing that can lead us to slip or slide into a war."