An American-Israeli citizen believed to have been held hostage in Gaza was killed on October 7 during the Hamas attack on Israel, the country’s military has said.

Omer Maxim Neutra, 21, from New York, was serving as a tank platoon commander at the time of the attack, the Israel Defense Force (IDF) reported, adding that his body was still being held in Gaza.

It is unclear what caused the IDF to make the announcement now. In previous cases when a hostage was declared dead, the finding was based on new intelligence and evidence.

Joe Biden said he was “devastated and outraged” by the news.

Neutra was “among the first to respond to Hamas’s campaign of cruelty — risking his life to save the lives of others,” Mr Biden said in a statement.

“To all the families of those still held hostage: We see you. We are with you. And I will not stop working to bring your loved ones back home where they belong.”