The number of people apprehended for illegally crossing the U.S.-Mexico border dropped sharply in February, which the Department of Homeland Security said is a sign of decreased traffic of illegal immigrants, and a sign that President Trump's immigration policies are already having an effect.

Apprehensions in February were 18,762, which is lower than any of the totals seen over the last five years, according to U.S. Customs and Border Protection statistics released late Wednesday.

Homeland Security Sec. John Kelly said the "unprecedented" drop from 31,578 apprehensions in January reflects a reduced flow of illegal immigrants, and indicates that President Trump's immigration policies are already helping to reduce that traffic.

"Since the administration's implementation of Executive Orders to enforce immigration laws, apprehensions and inadmissible activity is trending toward the lowest monthly total in at least the last five years," Kelly said in a statement.

While apprehensions — or the number of illegal aliens taken into custody by border agents — tend to decrease during the winter months, CBP historically has seen a 10 to 20 percent increase from January to February. The number of apprehensions went from 31,578 in January to 18,762 last month, a much sharper dropoff.

Kelly said the drop also indicates "many fewer people are putting themselves and their families at risk of exploitation, assault and injury by human traffickers and the physical dangers of the treacherous journey north."

One of the reasons for the drop may be attributed to the cost of travel for someone in Central America who wishes to make it to the U.S. Human smugglers or "coyotes" have hiked their prices by nearly 130 percent, according to DHS. Previously it would cost someone $3,500 for a coyote to guide them on their journey north, but since the election in November, those fees have jumped to $8,000 in some cases.

The increased fees may be due to increased risk smugglers take on as a result of Trump's change to detention policies of aliens. Last month, Trump essentially reversed catch-and-release policies so that those who are apprehended are not released into the interior of the country.

Although illegal entrant numbers typically rise during the spring and summer months, Kelly added that the administration's early efforts to thwart these problems indicate continued action will have an effect in the coming months.

"[T]he early results show that enforcement matters, deterrence matters, and that comprehensive immigration enforcement can make an impact," Kelly said.