America's poet laureate is challenging college graduates to be guided by love, not just tolerance, as they tackle the world's problems.

Tracy K. Smith offered the advice Friday during her keynote speech at Wellesley College's commencement ceremony in Wellesley, Massachusetts. Smith says tolerance is the "bare minimum" and asks graduates to find love for strangers across all divides as they address issues including school safety and immigration.

Smith's speech applauded younger generations for facing tough topics such as racial bias and for being "unafraid of the notion of struggle."

Smith is in her second term as poet laureate, a post appointed by the Library of Congress. Her poetry book "Life on Mars" won the 2012 Pulitzer Prize for Poetry.

Wellesley is a private women's college near Boston with about 2,500 students.