The Pentagon announced on Sunday that it was sending additional munitions to Israel and moving Navy warships closer to the country in a show of support, a day after Palestinian militants launched one of the broadest invasions on Israeli territory in 50 years.
Defense Secretary Lloyd J. Austin III said he had ordered the aircraft carrier Gerald R. Ford and five guided-missile cruisers and destroyers, which are already in the Mediterranean Sea, to the eastern part of the sea, near Israel. Officials said the ships were en route but would take a few days to arrive.
Mr. Austin also said the United States was increasing the number of Air Force fighter jets and attack planes in the region to “bolster regional deterrence efforts.” The assistance “underscores the United States’ ironclad support for the Israel Defense Forces and the Israeli people,” Mr. Austin said in a statement.
Mr. Austin’s announcement came as President Biden assured Prime Minister Benjamin Netanyahu of Israel in a call Sunday morning that military assistance was on its way and more would follow.
The promise of military might was designed by the Biden administration to reassure Israelis of the United States’ commitment to their security and to demonstrate resolve to Hamas and Israel’s other adversaries in the region. It comes despite months of tension between Mr. Biden and Mr. Netanyahu over disagreements about the prime minister’s pursuit of judicial reforms that many Israelis say are undemocratic.
In the call, Mr. Biden “discussed the taking of hostages by Hamas terrorists, including entire families, the elderly and young children,” according to a description of the call by the White House.
“The president emphasized that there is no justification whatsoever for terrorism, and all countries must stand united in the face of such brutal atrocities,” the statement added.
Pentagon officials said the deployment of additional forces was meant to deter Iran, Syria and any country or militant group from joining the conflict, as well as to provide enough ships, warplanes and other weaponry to protect Americans and American interests in the region.
Gen. Michael E. Kurilla, the head of the military’s Central Command, said in a statement on Sunday that his force “stands firmly with our Israeli and regional partners to address the risks of any party seeking to expand the conflict.”
A senior Biden administration official said just hours after the attacks that the United States did not have intelligence that Iran was directly involved in planning the assault on Israel. But the official, who requested anonymity to discuss diplomatic and military planning, said Iran had long been deeply connected to Hamas, offering it financial support and military equipment.
Secretary of State Antony J. Blinken said on NBC’s “Meet the Press” program on Sunday morning that the Israeli government had “asked for some specific additional assistance” as the country gears up for what Mr. Netanyahu has warned will be a prolonged conflict.
Mr. Austin said the Biden administration would supply the Israeli armed forces with additional equipment and resources, including munitions. U.S. officials declined to be more specific about particular weapons systems, but independent analysts said Israel would likely request more interceptors for its Iron Dome missile defense system as well as bombs and missiles for attack planes.
American officials said on Sunday that they were also working through plans to evacuate thousands of Americans from Israel if necessary in what is called a “noncombatant evacuation.” Pentagon officials emphasized that no decisions have been made but that they were working through options, including one that involves putting some Americans on the Navy ships to get them to safety.
The United States already provides Israel more than $3 billion in military assistance every year, and Mr. Blinken said that much of the equipment from that funding is already “in the pipeline” to be sent to Israel. The Pentagon also has positioned stockpiles of arms and ammunition worth about $2 billion at about six sites throughout Israel. The stockpiles provide weapons and ammunition for the Pentagon to use in Middle East conflicts, and the United States has also allowed Israel access to the supplies in emergencies.
Use of the stockpiles is set up in a “dual key” arrangement in which both countries sign off on their use. For instance, the Pentagon, with Israel’s permission, has tapped into the vast but little-known stockpile to help meet Ukraine’s dire need for artillery shells in the war with Russia.
Officials said the United States took only 155-millimeter artillery shells from the Israel stockpiles for use in Ukraine, which military analysts say Israel would not use in its fight against Hamas. If the fighting in the Middle East widens, the amount of supplies in the stockpiles could become an issue, analysts said.
Officials for the National Security Council declined to say whether the use of those stockpiles was under consideration. But Pentagon officials said on Sunday that discussions were underway to allow Israel to use them.
In the longer term, American lawmakers on both sides of the aisle said Sunday that they hoped Republicans could resolve their leadership struggle and select a House speaker so that Congress can act on further funding for Israel if needed.
“Given the situation in the Middle East with one of our closest allies in the world, it is critical that we bring this to a close expeditiously,” Representative Mike Lawler, Republican of New York, said on CNN’s “State of the Union” program.
Mr. Lawler and many of his Republican colleagues are fuming at the band of ultraconservative rebels who forced Speaker Kevin McCarthy out of his post last week, putting legislation and additional funding at risk.
“It wasn’t my idea to oust the speaker, and I thought it was dangerous,” Representative Michael McCaul, Republican of Texas and the chairman of the House Foreign Affairs Committee said Sunday on CNN. “I look at the world and all the threats that are out there. What kind of message are we sending to our adversaries when we can’t govern, when we’re dysfunctional, when we don’t even have a speaker of the House?”
Lawmakers signaled there would be bipartisan support to provide more aid to Israel, but the House would first need to elect a new speaker. Last week, Representative Matt Gaetz of Florida and seven other conservative lawmakers orchestrated Mr. McCarthy’s ouster, angry that he worked with Democrats last month to avoid a government shutdown.
“There will likely be a need for some additional appropriations,” Representative Hakeem Jeffries of New York, the top Democrat in the House, said on CNN, adding, “Congress should certainly be prepared to do that sooner, rather than later.”
Mr. Jeffries urged House Republicans to decide on a speaker.
The two Republican candidates to replace Mr. McCarthy both pledged their support for more Israel aid. On Fox News, Representative Jim Jordan of Ohio, the Judiciary Committee chairman, said his first move as speaker would be to offer assistance.
Representative Steve Scalise of Louisiana, the No. 2 House Republican, said on social media: “Make no mistake: The United States will always stand with Israel, our greatest ally in the Middle East.”
Luke Broadwater contributed reporting from Washington.