Actor Will Smith thrilled a group of youngsters in London on Friday (24May13) by giving a motivational speech at an event held by the city's mayor Boris Johnson.

The Men In Black star and his son Jaden, 14, attended a bash at City Hall to celebrate Johnson's Leadership Clubs, which help young people transition from primary to secondary school.

Smith addressed children at the event and told them, "I think it's hugely important to take these moments. I want to thank you all for being an example for your fellow citizens so I congratulate you on that."

Speaking about the bash, Johnson adds, "It is fantastic for students to meet Will and Jaden, two very inspiring figures."

Smith has previously supported pupils in the U.K. capital - in March (13), he showed up unannounced at a school in south London and hosted a question-and-answer session with youngsters.