President Trump later vowed that "the United States will not be a migrant camp ... not on my watch" after blaming Democrats for the child separation policy.
Faced with mounting condemnation of the practice, Trump dodged responsibility for splitting up families.
Trump does not back down from his migrant family separation policy even as condemnation and political risk mount.
The GOP lawmakers add to the mounting backlash Trump faces for his administration's "zero tolerance" practice.
The comment followed Nielsen's insistence that Trump has been "very clear that he agrees with the intel community" on Russian meddling.
Maryland is renowned for its crab industry, but this year several picking rooms are empty as Trump administration rules have clamped down on visas for temporary foreign laborers.
California Gov. Jerry Brown agreed Wednesday to mobilize up to 400 National Guard personnel at the request of the Trump administration but in doing so rejected any use of them for immigration enforcement or to help build a new border wall.
Perdue is the ninth Cabinet official in line for presidential succession.
President Donald Trump said he is "not a racist" despite reports of his derogatory comments about immigrants from Haiti and Africa.