U.S. Ambassador to Israel Jack Lew said on Monday that there are “indications” that Israel eliminated Hamas military chief Mohammed Deif in the Gaza Strip on Saturday. 

“There are still many questions regarding the results of the attacks against Mohammed Deif,” Lew said in a briefing for the American Jewish community hosted by the White House. “I can’t confirm whether it was successful or not, but there are indications that they have achieved it.” Israel has not confirmed that it had assassinated Deif, the head of Hamas’ military wing, the Izzedine al-Qassam Brigades, who had survived multiple Israeli attempts on his life over the past two decades. 

Lew’s comments come a week and a half before Israeli Prime Minister Benjamin Netanyahu is set to travel to Washington to deliver an address to a joint session of Congress, and as U.S. officials work to negotiate a cease-fire and hostage-release agreement between Israel and Hamas. Lew said that while he does not have advance knowledge of the contents of Netanyahu’s speech, slated for July 24, he “hopes that [the] speech to Congress next week will include a bipartisan message.” 

As tensions increase between Israel and Hezbollah and more than 70,000 people have been displaced from northern Israel since Oct. 7, Lew called the Iran-backed terrorist group in Lebanon a “very serious military force, much more sophisticated than Hamas [with] much more munitions reserves including precision-guided missiles and a military that is battle-trained but not worn out.”

“Israel is facing a military opponent that could do real damage to the country,” Lew said. “People in Israel broadly understand that but I’m not sure that they are thinking of what life will feel like [if war happens]… it’s something we should all want to avoid,” Lew said, adding that there is not an “easy resolution.” Displaced Israelis can’t go home, he said, “unless there is a negotiated agreement with some oversight mechanism to make people feel safe.”