Biden senior adviser Amos Hochstein in recent months has been serving as an envoy to mediators in the Middle East to try to keep tensions low between Israel and Hezbollah while also negotiating a ceasefire between Israel and Hamas, who have been at war for nearly a year, according to Axios.

Hochstein traveled to Israel last week to warn Israeli Prime Minister Benjamin Netanyahu against a war with Hezbollah, citing concerns that it would only upset an already chaotic Middle East. One day after Hochstein’s message to Netanyahu, Israel remotely detonated explosives planted inside thousands of personal communication devices being carried by Hezbollah operatives.

Hochstein was left furious because he wasn’t told of the plan in advance and felt that Israel had ignored his advice, U.S. officials, speaking on condition of anonymity, told Axios.