The US is “deeply concerned” about the sentencing of former Obama Foundation Scholar Hoang Thi Minh Hong to three years in prison, State Department spokesman Matthew Miller said in a statement.

“We reiterate our call on Vietnam to release all those unjustly detained and to respect the right to freedoms of expression and association for all persons in Vietnam,” he said.

In a Sept. 28 trial, Hong was sentenced to three years in prison and fined 100 million dong after being convicted of tax evasion, Thanh Nien newspaper reported on its website. Hong also must pay back taxes.

The environmentalist, 51, founded CHANGE, a Vietnamese NGO focused on endangered wildlife, climate change and reducing pollution that closed in October.

CHANGE generated revenue of more than 69 billion dong ($2.8 million) between 2012 and 2022, the newspaper reported, citing the indictment. The government said Hong directed employees to dodge tax payments of more than 6.7 billion dong by not issuing value-added tax invoices and following required accounting and paperwork procedures, according to the report.

The US called for transparent and impartial enforcement of tax laws in Vietnam, which would ensure that nongovernmental organizations can operate “without fear of undue targeting or prosecution,” Miller said.