Bangkok, Thailand (CNN) -- A Thai criminal court has sentenced a Thai-born American to 2 1/2 years in prison for insulting the monarchy, the latest case involving controversial laws for defaming, insulting or threatening the royal family.
Joe W. Gordon, whose Thai name is Lerpong Wichaicommart, cooperated during the investigation of his case and pleaded guilty, resulting in a lenient sentence, his lawyer said.
But the charge of writing and posting articles insulting the monarchy under the Southeast Asian country's lese majeste laws can yield a sentence as high as 20 years in prison in the Buddhist country, where the king is highly revered.
"A chokehold on freedom of expression is being created in the name of protecting the monarchy," Brad Adams, Asia director at Human Rights Watch, said in a report published December 2 on the laws.
King Bhumibol Adulyadej has pardoned foreigners in similar cases in the past. The lawyer, Anon Rumpa, said he plans to file for a royal pardon.
Speaking to reporters after the verdict, Gordon said he was "an American, not a Thai citizen."
An "American has rights and freedom to comment. In Thailand, there is limitation in expressing opinion," he said.
Gordon, 54, returned to Thailand last year after 30 years in the United States. He was arrested in May for posting a link on his blog to an unauthorized biography of the king, according to the Asian Human Rights Commission. He has been detained without bail since then.
State Department spokesman Mark Toner said the United States regards freedom of expression as a fundamental human right, "so we are troubled by the outcome of this case"
"We also have no higher priority, as you have often heard from this podium, than the protection of American citizens abroad, so we are engaged with the Thai authorities and consular officers from our embassy in Bangkok are in touch with Mr. Gordon and his family," Toner said Thursday. He said the United States has conveyed its views on the case to Thai authorities and doesn't see the incident "adversely affecting the overall relationship."
Elizabeth Pratt, consul general at the U.S. Embassy in Bangkok, called the sentence "too high for just expressing his free speech."
"We also respect the law of Thailand. We are trying to help Mr. Gordon in any way that we can."
The Human Rights Watch report cited a sentencing of a 61-year-old man to 20 years in prison for sending four text messages considered offensive to the queen. It said "many other harsh punishments" for violating the laws have been rendered in recent years.
"The severity of penalties being meted out for lese majeste offenses in Thailand is shocking," Adams said. "The new government seems to be responding to questions about its loyalty to the monarchy by filing countless lese majeste charges."
Human Rights Watch said the government has launched "a major campaign against alleged violations" of the laws since Prime Minister Yingluck Shinawatra took power last summer.
"The roots of the recent campaign appear to be found in the September 2006 military coup against Thaksin Shinawatra, the prime minister at the time, who was considered by royalists to be insufficiently loyal to the monarchy," the report said. Yingluck Shinawatra is Thaksin's sister.
The rights group said private people and entities "often misuse" the laws for political reasons. It has called on Thailand "to amend the laws so that private parties cannot bring complaints of lese majeste since no private harm is incurred."
"The heavy-handed enforcement of lese majeste laws has a devastating impact on freedom of expression in Thailand," Adams said. "A broad-based discussion is urgently needed to amend the laws to ensure that they conform with Thailand's international human rights obligations."