Defense Secretary Lloyd Austin told reporters in Brussels Thursday that the U.S. is not placing conditions on its military aid to Israel.

Austin said Israel is "a professional military led by professional leadership" and "we would hope and expect that they would do the right things in the prosecution of their campaign."

Austin said U.S. intelligence had no indication or warning that Hamas was planning such an attack.

Echoing other administration officials, Austin said, "We've not seen any indication that Iran was involved in the planning or the execution of this attack," though he added the U.S. will continue to focus on whether that is truly the case.

Austin said that the U.S. will "work urgently to get Israel what it needs to defend itself," including munitions and Iron Dome interceptors, and said helping Israel won’t affect the U.S. flow of military aid to Ukraine.

-ABC News' Luis Martinez

Israeli airline El Al said it'll fly on Shabbat -- which is from Friday night to Saturday night -- this weekend for the first time since 1982.

The flights from New York and Bangkok will bring soldiers to Israel.

A suspected Hamas terrorist appeared with a knife Thursday at the grounds of the music festival in southern Israel where hundreds of concertgoers were killed by Hamas this weekend.

Israeli soldiers immediately took down the suspect and took him into custody.

Secretary of State Antony Blinken on Thursday visited an Israel donation center, where he was greeted by applause and cries of “God bless America.”

Blinken dropped off his own contribution to benefit survivors who have lost everything.

He then spoke to Lior Gelbaum, a 24-year-old American-Israeli dual citizen, who was attending the music festival that was attacked by Hamas.

Through tears, she told Blinken that many of her friends were killed or taken hostage.

"Thank you for being here. It’s really important," she said. "And if there is any way to help -- first priority, first priority is our friends and family that are still in Gaza."

"We're thinking of them and trying to do everything we can. We want to bring them home," Blinken responded. "I admire your strength."

Another volunteer told Blinken he had just come from the fourth funeral of a friend who lost a child. The volunteer said all of the mourners had expressed that after concluding their mourning period, they would rebuild the country.

-ABC News' Shannon Crawford