Pelosi has frequently criticized China's suppression of human rights, but came under fire from some quarters last year for downplaying human rights during a trip to the country.
Pelosi said she disagreed with those suggestions, saying that she expressed her views to Chinese leaders in a way that was appropriate for her position during a head-of-state trip. Human rights in China and Tibet remains a "relentless pursuit of hers," she added.
"The Chinese government operates one of the most sophisticated operations in the world to control the Internet," she said Wednesday. "It is essential that technology companies not assist in efforts that violate human rights or prohibit free exchange of ideas."