WASHINGTON — In a clear warning to Syria to stop the transfer of advanced weapons to Islamic militants in the region, a senior Israeli official signaled on Wednesday that Israel was considering additional military strikes to prevent that from happening and that the Syrian president, Bashar al-Assad, would face crippling consequences if he retaliated.

“Israel is determined to continue to prevent the transfer of advanced weapons to Hezbollah,” the Israeli official said. “The transfer of such weapons to Hezbollah will destabilize and endanger the entire region.”

“If Syrian President Assad reacts by attacking Israel, or tries to strike Israel through his terrorist proxies,” the official said, “he will risk forfeiting his regime, for Israel will retaliate.”

The Israeli official, who had been briefed by high-level officials on Israel’s assessment of the situation in Syria, declined to be identified, citing the need to protect internal Israeli government deliberations. He contacted The New York Times on Wednesday.