71 killed in Israeli attack on Iran prison, official says

Israel achieved a great victory over Iran in the 12-day war, Israeli Prime Minister Benjamin Netanyahu said in a video statement in Hebrew Thursday.

"We fought valiantly against Iran -- and achieved a great victory. This victory opens up an opportunity for a dramatic expansion of the peace agreements. We are working hard on this," Netanyahu said.

"Along with the release of our hostages and the defeat of Hamas, there is a window of opportunity here that must not be missed. Not even a single day must be wasted," he added.

Separately, the Hostages and Missing Families Forum Headquarters issued a statement calling for a "comprehensive agreement" between Israel and Hamas to end the war in Gaza and bring the remaining hostages home.

"The era of partial deals is over," the Hostages and Missing Families Forum said in a release Thursday. "Why not leverage the achievements in Iran? This is the time for a comprehensive agreement."

"Upon assuming office, we were astounded to see how quickly a hostage deal came about," Udi Goren, cousin of hostage Tal Haimi, said in a statement released by the organization, addressing President Donald Trump directly. "But there’s one thing missing in order to move forward with your vision for the region: the deal of all deals - one that would bring ALL 50 hostages back and end the war."

-ABC News' Jordana Miller

Russian President Vladimir Putin said the situation in the Middle East is "calming down" and the conflict between Israel and Iran appears to be "in the past," in comments Thursday.

"This means that it will be possible to develop economic relations with all countries in the region, including Iran," Putin said.

In order to "preserve and consolidate the fragile truce" between Israel, Iran and the U.S., all parties need to return to the negotiating track as soon as possible, Russian Foreign Ministry spokesperson Maria Zakharova said in a statement Thursday.

"The settlement of the Iranian nuclear program, like the resolution of other crises in the Middle East, can only be achieved through diplomacy and negotiations. There is no reasonable alternative to this," Zakharova said in a statement, made in Russian.

"The specific practical initiatives put forward by the Russian President aimed at finding mutually acceptable solutions remain on the table. They have been communicated to all parties involved: the U.S., Israel and Iran," she said.

-ABC News' Tanya Stukalova and Anna Sergeeva

The centrifuges at Iran's Fordow nuclear facility "have suffered a great deal," International Atomic Energy Agency Director Rafael Grossi said Thursday.

"Given the scale and capacity of the military means used, we can deduce that the centrifuges have suffered a great deal, if [they] have not been destroyed,” Grossi said, originally in French.

When asked if it's possible that some of the technology or centrifuges at Fordow survived, are still operational or have been moved, Grossi said "it’s a hypothesis," that can’t be ruled out.

Grossi said while he understands the logic behind Israel and the U.S.’s decision to strike Iran’s nuclear facilities, he said he believed "there was a diplomatic path." Grossi acknowledged Iran was not cooperating in the U.S.-Iran negotiations before military intervention was taken.

"I could never say the solution was [using the] military. I’m not criticizing. It’s not my position to do so," Grossi said. "Until the day military action was triggered, Iran was not cooperating in the necessary way."

-ABC News' Leontine Gallois, Cindy Smith and Chris Boccia

Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, said after the first bomb struck the target, "the pilots stated, quote, 'this was the brightest explosion that I've ever seen. It literally looked like daylight.'"

"Unlike a normal surface bomb, you won't see an impact crater, because they're designed to deeply bury and then function ... All six weapons at each vent at Fordow went exactly where they were intended to go," Caine said.

-ABC News' Luis Martinez