You mean the US stopped funding the program. A program which had failed to produce an adequate airplane and proved that Israel was simply not up to doing anything once it had improved the Mirage III as much as it could. The 'Lavi' was a lemon.
Netanyahu: Most of Americans see eye to eye with Israel on dangers of Iran deal (Haaretz)
from the article: Israel to purchase 20 Lockheed Martin F-35 fighter jets