President Biden and first lady Jill Biden on Friday mourned the presumed death of an American-Israeli man believed to have been killed during militant group Hamas’s initial attack on Israel, which sparked the ongoing war in the region.

“Jill and I are heartbroken by the news that American Gad Haggai is now believed to have been killed by Hamas on October 7,” Biden wrote in a statement shared by the White House. “We continue to pray for the well-being and safe return of his wife, Judy.”

The fate of Judith Weinstein and Haggai has been unknown since the pair was on their morning walk when gunfire erupted on Oct. 7, according to the Associated Press. Weinstein is believed to be a hostage of Hamas.

Biden shared that the couple’s daughter, Iris Weinstein Haggai, was part of a meeting he had with the families of the hostages held by Hamas last week.

“Those families bravely shared with me the harrowing ordeal that they have endured over the past months as they await news of their loved ones,” he wrote. “It’s intolerable.”

“Today, we are praying for their four children, seven grandchildren, and other loved ones and are grieving this tragic news with them,” the president added.

He also renewed his vow to keep working to free the hostages.

“We will not stop working to bring them home,” Biden said.

Eight Americans were believed to be among the more than 240 hostages taken by Hamas on Oct. 7, a day on which roughly 1,200 Israelis were killed by the militant group.

More than 20,000 Palestinians in Gaza have been killed in retaliatory attacks carried out by Israeli forces, according to the Hamas-backed Gaza Health Ministry.