This policy is known as COLONIZATION.
Colonization refers to the action of settling down among foreign indigenous people and establishing control over them. Politically, this action is usually carried out by powerful countries. The Europeans were able to colonize Africa, America and India.
It was the "Chinese Exclusion Act" of 1882 that excluded an entire ethnic group from immigrating to the United States, partly because of economic fears but also because of blatant racism.
