Still, Lodi Gyari said Thursday's meeting in the White House between the Nobel Peace laureates would be an important boost for Tibet and for the broader U.S. commitment to human rights.

The Dalai Lama, who has met with every U.S. president for the last two decades, is a recurring thorn in U.S.-Chinese ties. China accuses him of pushing for Tibetan independence -- something he has repeatedly denied -- and considers meetings between the monk and foreign leaders to be an infringement on Chinese sovereignty.

This week's meeting follows a tense couple of months in what the Obama administration has called the world's most important relationship, highlighted by the recent U.S. announcement of a $6.4 billion arms sale to Taiwan, the self-governing democratic island Beijing claims as its own.