Over 1,600 people have been refused entry into the Northern Marianas since the fiscal year 2017.
U.S Customs and Border Protection staff declined entry to the potential tourists as they suspected they were entering the CNMI for unlawful purposes.
The figures have emerged as the CNMI sees a spike in people abusing the parole authority programme to either work illegally as construction workers or to give birth in the Northern Marianas.
The CNMI and the rest of the US have long dealt with the problem of birth tourism where late-term pregnant women travel so their babies can become US citizens.
Most recently the CNMI has looked into overstaying tourists who work in the construction industry.
The latter trend was exposed when one construction worker fell to his death at the Saipan casino site in March last year.