According to the US State Department, Ambassador Gary Locke met government officials and residents during a visit to Ngaba county, in north-eastern Tibet, last month.
During a press briefing in Washington, D.C. on Tuesday, October, 16, US State Department spokesperson, Victoria Nuland, described how Ambassador Locke visited villages and monasteries to: "learn more about how Tibetan people live and work, and to have a chance to talk to them."
The majority of the 55 self-immolations in Tibet since February 2009, of which at least 45 were fatal, took place in Ngaba, home to Kirti monastery, of which several of those who set themselves alight were monks and former monks.
All the self-immolaters shouted slogans demanding freedom for Tibetans and the return of His Holiness the Dalai Lama to Tibet.
Urging "better dialogue" between China and Tibet, Ms Nuland said: "We have grave concerns about self-immolations in Tibet and about the underlying grievances that the Tibetan people have.
"We have consistently urged dialogue between the Chinese Government and the Tibetan people with regard to those grievances."
Asked whether Ambassador Locke plans to share the experience of his visit with Congressional leaders and Tibetan communities in the US, Ms Nuland said: "Whenever we have members of Congress visiting China, they are always briefed by Ambassador Locke.
The various human rights issues in Tibet always come up, and he shares his impression and they talk together about how to raise these issues with the Chinese Government.
"He's not shy about that. If the Congress is interested in his trip, I'm sure that he will address any questions they have."
The announcement follows the publication on October 10 of a US Congressional report on China, which warned that a key communist party official's recommendation that the Chinese government should abolish ethnic minority status could "adversely affect the Tibetan people's cultural and linguistic identity."