Barbara Boxer, a top Jewish U.S. senator and the sponsor of major pro-Israel legislation, blasted Israeli Prime Minister Benjamin Netanyahu for lashing out at President Obama on Iran.

“I write to you as one of Israel’s staunchest supporters in Congress to express my deep disappointment over your remarks that call into question our country’s support for Israel and commitment to preventing Iran from acquiring nuclear weapons,” Boxer (D-Calif.) said in a letter sent Wednesday in a rare instance of a pro-Israel lawmaker making public an unhappiness with an Israeli leader. “Your remarks are utterly contrary to the extraordinary United States-Israel alliance, evidenced by President Obama’s record and the record of Congress.”

Boxer apparently was referring to Netanyahu’s remarks in Jerusalem on Tuesday in which he decried a lack of clarity from the “international community” – seen in Israel as code for the Obama administration – for failing to make clear what would trigger a U.S. strike on Iran as that country reportedly nears obtaining a nuclear weapon.