Israel will respond to any new attacks by Hamas militants with a “very powerful” response, Prime Minister Benjamin Netanyahu warned on Tuesday, thanking the US for bolstering his country’s air defenses during the top American diplomat’s visit to promote peace.

Secretary of State Antony J. Blinken arrived in the Middle East for the first time during the Biden administration to find a country on edge after more than ten days of war with Hamas that ended with a shaky cease-fire late last week.

In brief but direct remarks following their private meeting, Mr. Netanyahu expressed gratitude for the Biden administration’s consistent affirmation of Israel’s right to defend itself after coming under rocket attack from militants in the Gaza Strip. He said he and Mr. Blinken talked about how to stop Hamas, which controls Gaza, and how to help rebuild and improve the lives of the two million Palestinians who live there.

“If Hamas breaks the calm and attacks Israel, our response will be very powerful,” Mr. Netanyahu said after the meeting, standing next to Mr. Blinken. Mr. Blinken, for his part, sought to keep the conversation focused on reducing tensions and providing “urgent, humanitarian reconstruction assistance for Gaza.”

He stated that cementing the cease-fire “begins with the recognition that losses on both sides were profound.”

Mr. Blinken was expected to press Mr. Netanyahu to keep some border crossings into Gaza open so that humanitarian aid could reach at least 77,000 people who were forced from their homes during the fighting and are now sheltering in UN-run schools.

After nearly two weeks of Israeli airstrikes, hundreds of thousands of people have been cut off from electricity and clean water, and pockets of Gaza have been reduced to piles of rubble.

Mr. Blinken also emphasized the Biden administration’s intention to “rebuild our relationship” with the Palestinian people and the Palestinian Authority. He was scheduled to meet with Palestinian Authority President Mahmoud Abbas and Prime Minister Mohammad Shtayyeh later Tuesday in Ramallah.

The Biden administration’s goal in bolstering the authority is to marginalize Hamas, the militant group that controls Gaza and is considered a terrorist organization by the US. Hamas and the Palestinian Authority are bitter political rivals, and it is far from certain that the militants will relinquish any control of Gaza.

Mr. Netanyahu and other Israeli officials focused on what they described as another urgent threat to their stability in a series of discussions with Mr. Blinken throughout the afternoon. With American and Iranian diplomats meeting separately with world powers in Vienna, officials have noted progress in negotiations to bring both sides back into compliance with a 2015 nuclear deal in recent days.

Mr. Netanyahu said on Tuesday that he hoped the US would not simply resurrect the agreement that the Trump administration abandoned in 2018, in the hope of imposing stricter limits on Iran’s nuclear, missile, and military programs.

According to Mr. Netanyahu, the original agreement “paves the way for Iran to have a nuclear arsenal.” “We must also remember that, whatever happens, Israel will always have the right to defend itself against a regime bent on our destruction,” he said. Mr. Blinken stated that the US would continue to consult with Israel on negotiations “around the potential return to the Iran nuclear deal.”

In discussing broader peace efforts, Mr. Netanyahu stated that Israel was seeking American assistance in expanding its newly warm diplomatic relations with Arab or Muslim majority countries in the Middle East and North Africa. These ties, forged during the Trump administration, were put to the test during this month’s unrest between Israel and Palestinians, particularly when riots erupted at Al Aqsa Mosque in Jerusalem, one of Islam’s holiest sites.

“We believe that Palestinians and Israelis both deserve to live in safety and security, to have equal access to freedom, opportunity, and democracy, and to be treated with dignity,” Mr. Blinken said.