In Brazil, Blinken intervenes in a dispute with Israel.

Secretary of State Antony J. Blinken confronted President Luiz Inácio Lula da Silva of Brazil on Wednesday about his recent sharp comments on Israel, including the Brazilian leader’s comparison of Israel’s attacks in Gaza to the Holocaust.

The sparring showed how the enduring war in Gaza has continued to expand into a broader diplomatic problem for the United States, and how the war’s mounting death toll has spurred more nations to speak out against Israel’s offensive.

An intensifying dispute between Brazil and Israel broke out this week over Mr. Lula’s comments on Sunday that the only comparison to Israel’s killing of Palestinian civilians in Gaza is “when Hitler decided to kill the Jews.” It was a significant escalation of his previous rhetoric.

Since then, Prime Minister Benjamin Netanyahu of Israel has said Mr. Lula “crossed a red line,” Israel’s foreign minister called Brazil’s ambassador to the Holocaust museum and scolded him in front of the media, and Israel’s official account on X said Mr. Lula “went full on Holocaust denier.”

Brazil responded by recalling its ambassador to Israel “for consultations” and, according to Brazilian news outlets, discussed expelling Israel’s ambassador to Brazil if the situation escalated further.

In a 90-minute meeting in Brasília, Brazil’s capital, Mr. Blinken had a “frank exchange” with Mr. Lula, saying that he disagreed with the Brazilian leader’s recent statements and that the United States was trying to get hostages held by Hamas freed and get extended humanitarian pauses enacted, according to a senior U.S. State Department official.

The official spoke on the condition of anonymity while on the secretary’s flight to Rio de Janeiro. Mr. Blinken is in Brazil for meetings at a conference of foreign ministers from the Group of 20 nations.

A senior Brazilian official who spoke on the condition of anonymity said that the conversation about Israel was calm and respectful, and that Mr. Lula condemned both the Hamas-led attacks on Oct. 7, and the scale of Israel’s response, emphasizing the deaths of Palestinian children.

The conversation came at the end of the meeting, and Mr. Blinken opened the topic by discussing how his stepfather, Samuel Pisar, survived the Holocaust, the Brazilian official said. The biggest point of contention was over Mr. Lula’s stance that Israel was committing genocide in Gaza, the official said.

Both officials said the two leaders agreed on the goal of ending the conflict as soon as possible. However, Mr. Blinken emphasized that must be done under conditions that prevent Hamas from carrying out another Oct. 7-style attack and that end the long-running cycle of violence.

That the Israel-Gaza war has become a point of friction in the Biden administration’s dealings with one of the most influential nations in Latin America, one considered a leading voice in the region, illustrates how the conflict has thrown a shadow on American diplomacy around the world.