In a speech to a major conference held by a top U.S.-Israeli group, former Secretary of State Hillary Clinton implicitly criticized Donald Trump’s past positioning on Israel.

“We need steady hands, not a president who says he’s neutral on Monday, pro-Israel on Tuesday, and who knows what on Wednesday, because everything’s negotiable,” Clinton said at the American Israel Public Affairs Committee (or AIPAC) conference in Washington, D.C. Monday. “Well, my friends, Israel’s security is nonnegotiable. “

Clinton did not call out Trump by name. But the remarks reference previous statements made by the real estate mogul now leading the GOP White House race.

In February, Trump said he would be “neutral” in the conflict between Israel and Palestine, prompting outcry from Israeli allies and conservative hawks. At a debate earlier this month, Trump said he would be “somewhat neutral” in negotiations.

“I will tell you, I think if we’re ever going to negotiate a peace settlement … I think it would be more helpful is as a negotiator, if I go in and say I’m pro-Israel, but at least have the other side know I’m somewhat neutral to them so that we can maybe get a deal done,” Trump said then.

Trump is slated to speak at the AIPAC conference on Monday as well.