Democratic presidential candidate Julián Castro said Sunday that while the U.S. can take in more immigrants, he does not want to allow an "unlimited" amount of asylum seekers into the country.

"I agree with people that say, in theory, can’t we take everyone who would like to be in the United States" he said on ABC's "This Week" while clarifying his immigration plan.

"Nobody has called for that," he added. "I do believe, however, and put forward an immigration plan that would accept more people."

The former Housing and Urban Development secretary said a federal statute from the late 1970s allows the U.S. to accept up to 110,000 refugees annually, but about 30,000 or 40,000 are typically accepted. ADVERTISEMENT

Castro said he'd like to see the number of refugees accepted rise to the statutory limit.

"We're big enough to do that. There's been times in the history of this country where we've taken in a lot more and we became a stronger nation for it," Castro said.

"What's underlying this, and what [President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE] likes to count on, is the fear and paranoia he's stoking," he said.

Asylum seekers are most often desperate women and children fleeing horrible conditions, he added.

Castro also said the idea that they offer any national security or cultural threat "is bull."

Immigration has been at the forefront of Castro's campaign.

He renewed his call to decriminalize border crossing during last week's Democratic presidential debate.

Castro emerged stronger following the first round of debates, seeing his best fundraising day after his appearance.

A FiveThirtyEight analysis found Castro’s approval rating increased more than that of any candidate he shared the stage with last week.