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The Trump administration's efforts to curb immigration look like they're working, The New York Times reports.

A report released Monday by the National Foundation for American Policy projects policies like Trump's recently-expanded travel ban or the public charge rule preventing immigrants who may rely on welfare assistance from entering the country will alter legal immigration to the U.S. for quite some time. But change may also be noticeable rather quickly. Legal immigration had already declined by 11 percent between the 2016 and 2018 fiscal years, and the NFAP report predicts the decline will reach 30 percent by 2021.

That could have long-term consequences for U.S. economic growth, which NFAP says will slow because the average annual growth rate of the U.S. labor force will also sputter as a result of the immigration decline. The report says the rate will slow somewhere between 35 percent and 59 percent going forward if the policies remain in place. "The significant decline in the annual level of legal immigration means lower long-term economic growth may be Donald Trump's most lasting economic legacy," the report reads. Read more from The New York Times and view the full report.