Department of Homeland Security (DHS) Sec. Alejandro Mayorkas was ripped by one Republican lawmaker Tuesday over special agents within his department being reassigned to "make sandwiches" at the border for illegal immigrants being held there.

Sen. Josh Hawley, R-Mo., took aim at Mayorkas based on the testimony of a special agent from Homeland Security Investigations (HSI) who said at least 600 agents had been pulled off other cases and sent to the border amid a surge in migrants crossing into the country.

When pressed for a specific number of agents that had been reassigned, Mayorkas didn't have an answer, but said he'd be "very pleased" to provide it. He added that the reassigned agents were at the border "to fight the scourge of fentanyl."

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"That's not what the special agent is alleging. That's not what she said. She said that there were being taken off of fentanyl interdiction, taken off child exploitation cases, off of their other investigations into criminals to make sandwiches. That's her quote. You're saying that this is a lie? That she's wrong?" Hawley said.

Mayorkas argued there were "a number of law enforcement priorities," to which Hawley asked, "Is making sandwiches one of them?"

"Of course not, senator. We accomplish a tremendous amount —" he responded before Hawley jumped in, asking if the agent's testimony was wrong.

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"Making sandwiches for illegal immigrants? Is she wrong? This is one of your agents. Is she wrong? She says that there are 600, at least, special agents pulled off of other cases, sent down to the border to babysit illegal immigrants. Is she wrong?" he asked.

Josh Hawley and Alejandro Mayorkas

Sen. Josh Hawley, R-Mo., (left) and Homeland Security Sec. Alejandro Mayorkas (right). (Getty Images)

Mayorkas said DHS personnel were used "to achieve the maximum law enforcement objective possible. That is what we do."

"So you're not going to deny it?" Hawley asked.

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"I'm incredibly proud of what our people do every single day," Mayorkas said.

A department email sent to ICE agents in July and obtained by Fox News Digital said that due to the rise in migrant encounters at the time that HSI would be increasing its Operation Expanded Impact (OEI) numbers from 60 to 200.

Eagles Pass Texas migrants

Asylum seekers wait to be processed by U.S. Border Patrol agents after crossing the Rio Grande from Mexico into the United States on September 30, 2023, in Eagle Pass, Texas. Border security and immigration have become major issues in ongoing negotiations to fund the U.S. government. A recent surge in immigrant crossings at the U.S. southern border has overwhelmed authorities.  (John Moore/Getty Images)

According to the email, those agents were to deploy to key border sectors in Texas, Arizona and California. 

OEI was launched last year as part of a DHS effort to target transnational criminal organizations involved in smuggling and human activity.

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According to one HSI agent who spoke to Fox News Digital at the time, the deployed agents were often sent on short notice, and sometimes just help Border Patrol with the processing of migrants coming across.

"You're using skilled and trained special agents who are trained in criminal investigations and law enforcement tactics to guard people and to hand out food to individuals and help with processing," the agent said.

Fox News' Adam Shaw contributed to this report.