President Obama on Friday, reflecting on the 50th anniversary of former President John F. Kennedy's assassination, praised the work of the Secret Service and said he does not worry about his own safety.

"It's not something I think about," Obama told ABC News. "We have a Secret Service that does an outstanding job every single day."

"Obviously, tragedy reshaped the Secret Service in many ways, but they do an outstanding job and it's thankfully not something I spend a lot of time worrying about," Obama added.

The nation on Friday paid tribute to Kennedy, who was killed on Nov. 22, 1963, in Dallas. Obama ordered that flags at government buildings be lowered to half-staff.

Obama earlier this week, joined by first lady Michelle Obama, former President Bill Clinton and former Secretary of State Hillary Clinton, laid a wreath at Kennedy's grave at Arlington National Cemetery.

In the ABC interview, Obama said that Kennedy, during his short time in office, had left the country an "incredible legacy."

"JFK, in particular, captured the idealism, the ability to imagine and remake America to meet its ideals, in a way we haven't seen before or since," said Obama.

"I don't know of anyone who has had that same impact on a generation and inspired so many people as JFK has," the president added.

Obama’s interview with ABC News’ Barbara Walters is set to air next week.