WASHINGTON

US President Joe Biden has said the Secret Service is prohibiting him from going into crowds as he seeks to bolster Democratic presidential nominee Kamala Harris on the campaign trail.

"I'm not able to go out in the crowds anymore. The Secret Service doesn't let me," Biden told reporters at the White House after returning from the state of Pennsylvania late Monday. "They say it is too dangerous. No one gets to go out."

The Secret Service is the federal agency tasked with ensuring the safety of America's presidents, both sitting and former, as well as presidential nominees during election years.

The New York Times reported Aug. 15 that the agency ramped up protective details on former President Donald Trump after an attempted assassination against him in July. That included reassigning agents from Biden's team to Trump.

Trump was injured during the July 13 shooting but quickly returned to campaigning.