HOUSTON -- A prominent blogger freed from prison in Vietnam on condition that she live in exile in the United States says she is glad to be reunited with her family and that she knows she is not alone in advocating for freedom.

Nguyen Ngoc Nhu Quynh was smiling when she emerged from the George Bush Intercontinental Airport in Houston on Wednesday night to be greeted by a crowd, many of them Vietnamese-Americans. Her two young children and her mother travelled with her.

Quynh blogged as "Mother Mushroom" about human rights and industrial pollution. She was arrested in Ho Chi Minh City in 2016 and sentenced to 10 years in prison on charges of defaming Vietnam's Communist government -- a conviction that drew criticism from some governments and human rights groups.

Speaking to reporters upon her arrival, Quynh said that even though she had prepared herself for seeing her family again, she was overwhelmed.

"I was shocked when my son and my daughter hugged me on the plane," Quynh said. "We had to wait (for this moment) for two years."

Quynh could not immediately be reached for comment on Thursday.

Quynh said she knows she is not alone and that she and others will still speak up for freedom in her native country.

Vietnam has stepped up a crackdown on dissent over the past two years with scores of activists and bloggers jailed for national security-related offences.

Amnesty International says there are more than 100 "prisoners of conscience" in Vietnam.

The U.S. Embassy welcomed Quynh's release and said it would continue to press for the release of other "prisoners of conscience."

"We will continue to call on the government of Vietnam to immediately and unconditionally release all prisoners of conscience and allow all Vietnamese citizens to express their political views without fear of retribution," U.S. Embassy spokeswoman Karen Tang said in a statement Thursday.

Quynh was released as U.S. Secretary of Defence Jim Mattis visited Vietnam, aiming to boost military co-operation between the two former foes amid growing Chinese assertiveness in the South China Sea.

U.S. State Department spokeswoman Julia Mason said Thursday that Quynh had previously told U.S. officials she wanted to come to the United States if released from prison.

Quynh's immigration status in the U.S. was not immediately known.

In an email, U.S. Citizenship and Immigration Services said due to privacy reasons, it can't comment "on whether or not individuals have applied for immigration benefits or any decisions involved in the adjudication process."

In a statement, the Committee to Protect Journalists said Quynh plans to live in Houston. The Texas city has the third-largest Vietnamese population in the U.S., according to the Pew Research Center.

"We are greatly pleased that Nguyen Ngoc Nhu Quynh is finally free, but strongly reiterate that she never should have been imprisoned in the first place," said Shawn Crispin, the committee's senior Southeast Asia representative. "Authorities should follow through on the move by releasing all the other journalists still wrongfully held behind bars in Vietnam."