Thailand's revered monarch King Bhumipol Adulyadej was unable to deliver his annual address to the nation Thursday because of health complications.
Many in Thailand were looking forward to the speech as the nation seeks an end to its ongoing political crisis. The King, who will be 81 on Friday, speaks to the Thai people on his birthday.
Speaking in his father's place, Crown Prince Vajiralongkorn told listeners that King Bhumipol was suffering from a mild illness.
The crown prince said the King thanks them for their well wishes, and wants the people to have strong mental and physical health to perform their duties.
Crown Princess Sirindhorn, who also spoke, said her father has a throat problem that has left him barely able to eat. She says however his condition is not serious.
The speech comes one day after anti-government protesters ended more than six months of demonstrations that included a takeover of the prime minister's compound and Bangkok's main airports.
The eight-day siege of the airports, which ended Wednesday, stranded more than a quarter-million tourists and devastated Thailand's vital tourism industry. Airport officials say normal operations will resume Friday.
The People's Alliance for Democracy ended their protests after Thailand's Constitutional Court disqualified Prime Minister Somchai Wongsawat from holding his post and banned leaders of the country's top three parties. The court found them guilty of voter fraud.
The protesters are strong supporters of the monarchy, while Thailand's rural poor are aligned with ex-Prime Minister Thaksin Shinawatra, who was deposed in a 2006 military coup.
The People's Alliance for Democracy considers Mr. Thaksin corrupt and authoritarian. It accused Mr. Somchai of acting as a proxy for the former prime minister.
Mr. Somchai's People Power Party and two coalition partners were dissolved by the court's order. But members of the banned parties remain a dominant force in parliament. They are reorganizing in new parties and say they plan to form a new ruling coalition.
Protest leaders have warned they will resume demonstrations if the new government is allied with Mr. Thaksin.