Issara`s group is unhappy with the U.S.-based NGO for calling for a review of section 112 of Penal Code 9 (the country`s lese majeste law) and for advocating for those found guilty under the law.
Issara was allowed access inside the Embassy where he submitted a letter to new U.S. Ambassador Glyn T Davies.
"The actions of Human Rights Watch are not neutral and are biased on one side of the political spectrum," it claimed.
The lese majeste laws prosecute those seen to defame the reigning monarch, his family, and the heir apparent and his family.
Critics, including Human Rights Watch, argue that the law is being unfairly abused for political purposes.
While the governing body of monks, or the Sangha, generally avoid politics and discourages involvement in politics by individual monks, there have been instances of monks becoming involved in political issues.
During the pro-Shinawatra "Red Shirt" protests of 2010, several monks traveled with protesters and conducted blessing ceremonies on their behalf.
Issara was not only involved in 2014 political protests, but led one of the largest factions marching in opposition to the government.
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