U.S. President Joe Biden is planning to kick out one of the most senior officials in the U.S. Customs and Border Protection, according to sources familiar with the matter.

The Department of Homeland Security political appointees had decided to replace CBP Deputy Commissioner Robert Perez as the second-highest official of the agency.

Perez got the position in July 2018. He was then responsible for trade, travel, immigration, and national security at borders, according to a Washington Examiner report.

Perez was transferred to an office in Tucson, Arizona. The 29-year public servant is now planning to retire.

Troy Miller was expected to fill the position Perez will be leaving.

On April 7, CBP posted on their website Miller was performing the duties of Commissioner.

Miller will be overseeing more than 60,000 employees while also managing a budget of more than $15 billion, according to the U.S. CBP website.

Miller will be directing CBP's three core goals, which are counterterrorism, border security, and trade enforcement.

He previously served as the Director, Field Operations for CBP's New York Field Office.

He also had an earlier stint at National Targeting Center as Executive Director.

Office of Intelligence and Investigative Liaison also had Miller as the Acting Assistant Commissioner from 2013 to 2015.

READ MORE: Biden Admin May Have To Restart Border Wall Construction To Fill Holes

Border Patrol

Some U.S. border patrol agents said that they are struggling with Biden's border policies, adding that they are encouraging early retirement.

Meanwhile, others are buying unofficial coins that say U.S. Welcome Patrol, according to a Reuters report.

There were also reported dissatisfaction among some rank-and-file members of U.S. CBP over Biden's reversal of Trump's hardline immigration policies.

Brandon Judd, president of the National Border Patrol Council, criticized Biden in a news conference with Republican lawmakers on Capitol Hill.

Judd represents the labor union with three-quarters of around 20,000 border patrol agents.

Judd further said that he is confident to say that Biden had caused the migration crisis at the border.

Meanwhile, Biden administration officials defended the changes in the law enforcement agency.

The officials said that the current president's approach stemmed from solutions and effective management.

Gil Kerlikowske, who was CBP commissioner for three years under former President Barack Obama, said that there are people inside the agency who disagree with the politically outspoken union.

However, Kerlikowske said that many may not speak out their oppositions.

Tucson Police Chief Chris Magnus's nomination was also among the frustrations of those inside the agency.

Kerlikowske defended Magnus's nomination, saying that if the Tucson Police Chief were to be confirmed as head of the immigration agency, empathy and compassion will be a standard.

Migration Crisis

In March, CBP agents had met 172,000 illegal migrants mainly from Central America and America. It marked a more than 70 percent increase from February, according to a Foreign Affairs report.

Many have labeled the migrant surge at the border as a crisis. However, Biden had earlier refuted the idea that what was happening at the border was a crisis.

The president then tapped U.S. Vice President Kamala Harris to address the migration issue through diplomacy and discussion with the leaders of the countries with the highest migrants, such as Honduras, Guatemala, and Mexico.

READ NEXT: 10 of 13 Killed in California Crash Were Mexicans Who Entered U.S. Through Hole in Border Fence

WATCH: GOP Blasts Biden on Immigration Amid Migrant Influx at U.S-Mexico Border - from Bloomberg Quicktake: Now