The U.S. government has been a loud critic of Vietnam’s human rights record, urging Hanoi to stop jailing pro-democracy dissidents and to allow followers of all religions to worship freely.
Mr. Michalak told reporters last month there was a spike in arrests and convictions in 2010 involving people peacefully expressing their views.
Vietnam’s government does not tolerate any challenge to its one-party rule. It maintains that only lawbreakers are jailed.
Lee contributed to this report from Washington.