An independent U.S. government panel is urging Vice President Joseph Biden to raise the issue of religious freedom during his visit to China.

In a letter sent to Biden on the eve of his trip, the Commission on International Religious Freedom encouraged the vice president to “speak candidly” to Chinese leaders about the importance of religious freedom in U.S.-China relations “and to be a strong voice” for those imprisoned for peacefully advocating universal freedoms.

The commission discussed the repression of human rights activists such as lawyer Gao Zhisheng, who disappeared five years ago, Nobel Peace Prize winner Liu Xiaobo and others. The letter also touched on the plight of the Shouwang Church in Beijing, whose weekly public prayer services have led to members being harassed and arrested.

The commission urged Biden to become a “voice for the voiceless” by raising less prominent cases involving Buddhists, Catholics, Muslims and adherents of Falun Gong.

The U.S. Commission on International Religious Freedom is an independent, bipartisan government panel created in 1998. The panel's mission is to review the facts and circumstances of violations of religious freedom around the world.