(IsraelNN.com) Israel's Jewish population is more than 5.5 million, surpassing the slightly more than 5.2 million in the U.S., according to official census statistics.

Although non-orthodox definitions of who is a Jew change the American Jewish population to be between 6 and 9 million, Israel's leading demographer, Prof. Sergio Della Pergola of Hebrew University, thinks that even those figures will be surpassed by Israel in several years.

If the number of American Jews continues to decline because of increasing intermarriage, Israel undisputedly will be the largest Jewish center in the world, even according to non-traditional definitions of who is a Jew.

The Central Bureau of Statistics estimates that the population growth of Jews in Israel is slowly declining from 1.8 per cent, but these projections do not take into account the possible phenomenon of massive immigration.

Prime Minister Ariel Sharon last year instructed the Jewish Agency to work on a program to encourage hundreds of thousands of American Jews to move to Israel in the next few years.

Israel ceased being the center of world Jewry towards the 10th century, when Jews fled the murderous Crusades. Della Pergola estimates that the Jewish population in the world today would be more than 100 million if it were not for anti-Semitism and intermarriage.