Israel's interior minister has called for reforming the law that grants Jews around the world Israeli citizenship.
New arrivals with Jewish ancestry are quickly made Israeli citizens
Meir Sheetrit said citizenship should be earned by a strong commitment to Israel and not granted automatically.
He was addressing the governors of the Jewish Agency, which is responsible for promoting Jewish immigration to Israel.
He said funds should go towards helping deprived immigrant communities already in Israel rather absorbing more "lost tribes" living in Africa and Asia.
Mr Sheetrit referred to the rise of neo-Nazism among young immigrants from the former Soviet Union as proof that the granting of automatic citizenship to people defined as Jews was not working.
Israel's Law of Return is one of the state's founding principles, and some Jewish Agency members have strongly criticised the minister.
Reports of the speech in the Israeli press said Mr Sheetrit wanted new immigrants to reside in Israel for five years before being considered potential citizens.
They would have to swear allegiance to the country and pass a language test to ensure their knowledge of Hebrew is sufficient.
Analysts say facilitating immigration of the larger number of Jews to Israel is a key factor in countering the demographic challenge posed by the growing Palestinian Arab population in Israel and the occupied territories.