It was the first known security breach at the White House since Trump took office nearly two months ago.
The Secret Service said in a statement that the individual, whom it did not identify, was arrested on the south grounds without further incident after climbing an outer perimeter fence near the Treasury Department and East Executive Avenue at about 11:38 p.m. Friday.
No hazardous materials were found during a search of a backpack the individual carried over the fence, the agency said.
"Secret Service did a fantastic job last night," Trump said Saturday from his golf club in Northern Virginia. Trump described the intruder as a "troubled person" and "very sad." He was briefed on the matter Friday night.
Homeland Security Secretary John Kelly also was briefed on the incident, the Secret Service said. Kelly was among several Cabinet secretaries and senior White House staff members who attended a working lunch with the president at the Trump National Golf Club.
The Secret Service also said a search of the north and south White House grounds found "nothing of concern to security operations."
The agency didn't provide an update Saturday on the individual's status. Standard practice is to turn intruders over to the local police department.
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