(NewsNation) — Israel launched a series of airstrikes on Gaza that killed more than 400 Palestinians and ended a ceasefire that was in place since January.

Israeli Prime Minister Benjamin Netanyahu’s office said the strikes were ordered after Hamas refused to release remaining hostages in Gaza. The two sides were negotiating the second phase of the ceasefire.

The release of the last remaining Israeli American hostage, 21-year-old Edan Alexander, has been in the works since Hamas offered to release him last week. The Trump administration says Hamas was adding more demands to ceasefire negotiations.

Jason Meister, a family friend of the Alexanders and former Trump campaign advisory board member, said peace through strength is important when it comes to bringing remaining hostages home and ending the war with Hamas.

“If we want peace, we have to be willing to use military strength,” Meister said. “It also requires a clear condemnation of Hamas.”

Adi Alexander, the father of Edan Alexander, said Hamas never responded to the deadlines for returning hostages. Alexander said he remains hopeful about his son’s return, with the two sides going back to Egypt to negotiate.

“It’s encouraging, but at the same time, it’s very disturbing,” Alexander said.