Bieber was recently hit with accusations claiming that he fathered the child of 20-year-old Mariah Yeater after a concert last year.
The 'Never Say Never' singer has since undergone a DNA test to prove that he is not the child's father and has vehemently denied ever having met Yeater.
Usher, who has mentored Bieber throughout his career, urged the 17-year-old to keep his head up, telling MTV News: "[He needs to] stay strong. And know that all of this comes with the territory."
Bieber has described the paternity allegations as "unfortunate", but promised to stay positive.
Usher was recently confirmed to perform at The Grammy Nominations Concert Live!! - Countdown To Music's Biggest Night on CBS later this month.
Watch Justin Bieber's video for 'Somebody to Love' featuring Usher below: