Speaking from the hospital where he has been since last year, King Bhumibol Adulyadej, 82, addressed a group of newly appointed judges.
"I would like all you to preserve honesty," he said, adding that "it will be a way to help the country to be progressing and stabilized at the same time."
He told the judges they could "be seen as model" for people who work in all sorts of jobs.
The king added that in performing their duties, the judges "would help to uphold justice and order of the country, and this is very important. If you do follow your oath strictly, it will help bring order to the country, certainly."
King Bhumibol, the world's longest reigning monarch, wields little political power, but is revered and enjoys immense popularity.
He was admitted to the hospital last September after complaining of fever and fatigue.
Meanwhile, the political crisis in the country shows no immediate sign of abating. Negotiations between the government and the anti-government protesters, known as "red shirts," are stuck, and tensions are mounting. Another group of protesters, called the "multi-colored shirts," are urging the government to take tougher action against the red shirts.
On Sunday the country's prime minister acknowledged he did not expect protesters would use weapons and apply violence toward authority.
Speaking on national television, Prime Minister Abhisit Vejjajiva made the admission a day after he rejected a call from anti-government protesters to dissolve the country's parliament in 30 days. Abhisit said other groups' political opinions must be taken into consideration before any such action is taken.
More than two dozen civilians and military personnel have died since protesters began occupying key tourism and shopping areas in Thailand's capital.
Red Shirt leaders offered Friday to return to the negotiating table -- but only if the government meets certain demands, including lifting a state of emergency and accepting responsibility for the deaths of protesters earlier this month, said Weng Tojirakarn, a co-leader of the group.
On the government's side, spokesman Panitan Wattanayagorn told on Saturday that there was no counter-proposal to get the negotiations back on track.
"We need to make sure negotiations take place under a conducive environment," Panitan said, explaining that previous attempts to talk to opposition leaders had been derailed due to threats against government officials.
Other conditions that must be met before any negotiations could take place include having protest leaders make sure there will be no further expansion of demonstrations into other districts and no threats to government officers, the government spokesman said.
"These conditions are very critical for peaceful negotiations," Panitan explained. "Negotiation is the only way out in the end, but... we need to stabilize the situation first."
He cited the fact that several demonstrations were taking place "by different 'shirts' and colors," and said that all demonstrators must observe the rule of law and "peace and civility will be restored first."
His remarks came as tension remained high on the streets of Bangkok, where a political standoff has gripped the country for several weeks. The Red Shirts have been clashing with the Thai military in a Bangkok area that serves as a financial hub. Another co-leader of the Red Shirts, Veera Muskapong, met with foreign diplomats Friday and told them he might meet with the government if it meets certain conditions.
Abhisit, meanwhile, huddled with the chiefs of the country's armed forces early Friday after a string of grenade attacks killed at least one person and wounded dozens of others.
Deputy Prime Minister Suthep Thaugsuban said in a televised address that the grenades were launched from the area where the Red Shirts have been encamped for weeks, but the protesters denied any responsibility for the attacks.
