The Trump administration won’t be able to remove every undocumented migrant inside the United States, and the success of its promised mass deportation plan is “going to be based on what Congress gives us,” the administration’s new “border czar” Tom Homan told ABC News.

“I’m being realistic,” Homan said in an interview with ABC “This Week” co-anchor Martha Raddatz. “We can do what we can with the money we have. We’re going to try to be efficient, but with more money we have, the more we can accomplish.”

Immigration and Customs Enforcement doesn’t currently have enough funding from Congress to detain all of the undocumented immigrants that the Trump administration says it hopes to arrest, Homan said, so the scope of its enforcement operations is dependent on the scope of funding from Congress.

“The more money, the better I’m going to do,” he said.

Watch more of Martha Raddatz’s interview with Tom Homan Sunday on ABC’s ‘This Week’

Homan said success comes down to this: “Take as many public safety threats off the street as possible.”

That includes deporting “every illegal alien gang member in this country, including Tren de Agua,” the Venezuelan cartel, he added.

“When we see the crime rate from illegal aliens go down, that’s success,” he said. “Every public safety threat removed [from] this country is success. Every national security [threat] we find and remove from the country is a success.”

In the interview airing Sunday, Homan said the U.S. government for the first time ever used military aircraft to transport migrants back to their home country, and it will now be a daily occurrence.

According to U.S. officials, the U.S. military on Thursday flew more than 150 migrants to Guatemala on two separate flights.