The Israeli military said the young people were struck on Saturday by an Iranian-made rocket carrying a 50-kilogram warhead that Iran-backed Hezbollah fired at a football field in the Druze Arab town of Majdal Shams.

Hezbollah has denied responsibility for the strike.

"We are determined to bring the Gaza conflict to a close. It's gone on for far too long. It's cost far too many lives. We want to see Israelis, we want to see Palestinians, we want to see Lebanese live free from the threat of conflict and violence," Blinken said.

"We're in conversations with the government of Israel. And again, I emphasise its right to defend its citizens and our determination to make sure that they're able to do that," he said in Tokyo.

"But we also don't want to see the conflict escalating. We don't want to see a spread. That has been one of our goals from day one, from October 7 on, and we'll continue to do that.