WASHINGTON — Two members of President Trump’s cabinet appeared to retreat on Sunday from one of Mr. Trump’s signature campaign promises: to “immediately terminate” an Obama administration executive order meant to protect the legal status of children of undocumented immigrants.

“We’re not targeting them,” the homeland security secretary, John F. Kelly, said of such children in an interview on CNN’s “State of the Union.”

In a separate interview, on ABC’s “This Week,” Attorney General Jeff Sessions affirmed that the federal government did not “have the ability to round up everybody.”

Mr. Kelly said on CNN that “these people are caught between the law,” adding that “the president obviously is sympathetic.”