Recently appointed US ambassador Glyn T Davies called on Thailand to decriminalise "freedom of expression" offences and stop trying civilians in military courts in his first speech at the Foreign Correspondents' Club of Thailand on Wednesday night.
Mr Davies, who is in his ninth week in Thailand, again called for a swift return to democracy, adding this required open public debate while all institutions must ensure that people feel safe to speak even though they have different views from the government.
Freedom of expression has been curtailed by the National Council for Peace and Order since last year's coup and many people have been arrested for protesting or expressing opposition to the military-installed government.
The American diplomat said freedom of expression was needed to ensure broader debate and political stature, and any criminal or royal defamation rulings handed down by military courts upon civilians or charges filed against investigative journalists would deter freedom of expression.
"I respect and admire His Majesty King Bhumibol, whom we could lay claim a little bit to as a son of the US and who has done so much for not only Thailand and the US but the region. But I think no one should be jailed on lese majeste charges," Mr Davies said.
He stressed: "Freedom of expression should not be criminalised. Civilians should not also be tried in military courts."
Asked if he understood Thai-style democracy, he said he was aware that the country has "a very special ancient culture and respect for others is important. I also know that His Majesty the King is revered".
He added: "But democracy has universal, not American, principles which included self-determination and free speech."
Mr Davies, with 35 years of experience in the foreign service, said the US wants to resume full cooperation and see Thailand re-emerge as a strong, capable democracy leader in the region. But ultimately it was the power of the people that would create stability in the country.
"Thai people from everywhere in the world and from all walks of life have a key role to play. So I hope it will be an inclusive process that will lead to long-term stability," he said.
He praised the role of journalists in particular in exposing problematic issues like human trafficking and corruption.
"Corruption can be best dealt with through a free press, investigative journalism and an independent judiciary as well as strong law enforcement," said Mr Davies.
The envoy has met Prime Minister Prayut Chan-o-cha, Deputy Prime Minister Prawit Wongsuwon, Deputy Prime Minister Wissanu Krea-ngam and other senior government officials as well as Privy Council president Prem Tinsulanonda and His Majesty's Private Secretary Krit Karnchanakoonchorn.
He rejected the notion US policy has changed in response to closer ties between the Thai junta and China, but he acknowledged the tone and gesture might have changed.
"No, we didn't lose Thailand to China.... It's not conquest in colonial terms. Thailand and the US see in each other mutual benefits and we value freedom and independence," he said.