Border Patrol Chief Michael Fisher said today that he will never “feel comfortable” telling Congress that the border has been secured or that the government has a “scientific method” for tracking how many people attempt to enter the country illegally.

“When there are no more bad people looking to come into this country illegally between the ports of entry,” Fisher told the Senate Homeland Security and Government Affairs Committee. “That’s the only time that I would feel comfortable [enough] to come before this committee and others and suggest that the border is definitively secured. It is not an easy process.”

The committee hearing was focused on the Gang of Eight’s immigration proposal. Fisher also told lawmakers that he doesn’t know how many people are trying to enter the country illegally.

“I don’t offer, even in the context of an effectiveness ratio, that somehow this is a scientific method and that I can assure the chairman and this committee or the American people that, at any given time, we will be able — on 4,000 miles on the northern border and 2,000 miles on the southern border — be able to say with 100 percent certainty the amount of people that enter and of that number how many people we apprehend,” he said. “The terrain does not allow it, the vastness of our borders don’t allow us [to do so].”

He then added, “it does not mean we cannot accomplish that,” but it’s not clear what he meant because Sen. Ron Johnson, R-Wis., interjected with a question about whether he has put together a plan to secure the border.

Sen. Tom Coburn, R-Okla., had earlier pressed Fisher about whether they actually knew the number of people coming into the country.

“A path to citizenship is in this bill and it’s based on the fact that the border is going to be controlled,” Coburn reminded Fisher.

“You’re not going to sell the vast majority of Americans on immigration until you [convince] them that you have the control.” Coburn did note that the statistics on border security are more accurate than ever, but he maintained that they need improving because of the risk that terrorist such as the 9/11 hijackers exploit a border security weakness.