The United States on Monday demanded that Vietnam immediately free a blogger who was sentenced to 10 years in prison after posts critical of the government.

The State Department said it was “dismayed” by the sentence handed last week to Truong Duy Nhat, a regular contributor to US-backed Radio Free Asia.

“The United States calls on Vietnam to immediately release Nhat and all prisoners of conscience and to allow all individuals in Vietnam to express their views freely and assemble peacefully without threat of retribution,” State Department spokeswoman Morgan Ortagus said in a statement.

She said that freedom of expression is in accordance with Vietnam’s “international obligations and commitments” as well as Vietnam’s own constitution.

Nhat mysteriously appeared in a Vietnamese prison in March 2019 after fleeing to Thailand seeking refugee status with the UN High Commissioner for Refugees.