Precise data differ between the different governmental sources or Jewish organizations, not to mention, how does one define an Israeli?

A recent event organized by IAC in Los Angeles. An estimated 15,000 Israelis attended. – Source: Haaretz
Drawing on estimates of Israeli government ministries and the Agency, Sagi Balasha, CEO of the Los Angeles-based Israeli American Council which represents Israelis and promotes their interests, believes that there are between 500,000 and 800,000 Israelis living in the United States.