Katie Tobin, a top White House adviser on migration issues, is leaving after three years within the National Security Council, according to reports.
Tobin had originally planned to leave her position as senior director for transborder security last summer, but the Biden administration persuaded her to stay on through the end of the year, NBC News reported.
Tobin’s departure comes as the administration faces intense criticism over its handling of migrants illegally crossing the southern border.
Tobin was part of a U.S. delegation that traveled to Mexico to discuss what can be done to decrease illegal crossings, and she led planning for the end of the Trump era Title 42 last year.
National Security Advisor Jake Sullivan called Tobin "tenacious and dedicated" on migration efforts in a statement to NBC News.
He added, "We will miss Katie’s positivity and thoughtful contributions on an incredibly complex portfolio, but wish her well."
Fox News Digital has reached out to the White House and National Security Council for comment.
NOEM PLEDGES TO SHIP RAZOR WIRE TO TEXAS IF BIDEN STOPS ABBOTT
A replacement for Tobin has not been selected, an NSC spokesperson told NBC News.
Just this week, Border Patrol agents near El Paso, Texas, caught 40 migrants involved in two human smuggling operations as the border hit its highest rate of migrant encounters last month, blowing away previous statistics.
Sources with Customs and Border Protection told Fox News Digital that migrant encounters hit a staggering 300,000 incidents in the last month of 2023, reaching a level thought unimaginable just years ago.
Between Dec. 1 and 31, more than 302,000 migrants were documented attempting to cross the U.S. southern border.
CLICK HERE TO GET THE FOX NEWS APP
It is the highest total for a single month ever recorded. It is also the first time migrant encounters have exceeded 300,000.
Fox News' Michael Dorgan contributed to this report.
