President Donald Trump will no longer pursue adding a question on citizenship to the 2020 US census questionnaire.
Instead, he said he had directed officials to obtain the information through an executive order for government agencies, as court challenges would have delayed a census.
"We will leave no stone unturned," Mr Trump said.
The retreat follows a long fight over the inclusion of the question, which the Supreme Court had blocked in June.
"We are not backing down on our effort to determine the citizenship status of the United States population," the US president said.
The order will require government agencies to hand over documents regarding citizenship.
"As a result of today's executive order we will be able to ensure the 2020 census generates an accurate count of how many citizens, non-citizens and illegal aliens are in the United States of America," Mr Trump said at the White House.