"Relations between the Thai Royal Family and Japanese imperial family are very close and intimate," said Sakutaro Tanino, press secretary to the emperor at a press briefing on Wednesday.

"It is rare for our emperor or crown prince to visit the same country more than once. Eight times is a historic record," he said.

He said the emperor had been to Thailand six times as crown prince and twice as emperor. Thailand was also the first country the emperor visited after acceding to the throne in 1989.

The emperor and empress arrived in Thailand on Sunday to congratulate His Majesty the King on the 60th anniversary of his accession to the throne.

"The emperor feels enormous respect and admiration towards the King and Queen of Thailand … on this happy occasion, their majesties wanted to come personally to give their congratulations," said Tanino.

During their stay, the two royals visited the former capital city Ayutthaya - as well as Chulalongkorn University.

On Tuesday, the emperor and empress visited the historical study centre in Ayutthaya and listened to a detailed explanation about the city's long history, said Tanino.

He said the emperor has a strong interest in historic sites and very much hoped to visit the ancient city of Ayutthaya even prior to their visit.

Tanino said their majesties were very impressed by the kindness of HRH Crown Princess Maha Chakri Sirindhorn, who accompanied them.

On Monday, their majesties visited Chulalongkorn to inspect a Japanese-Thai joint research project on multi-dimensional relationships between humans and chickens initiated by their second son, Akishino.

Tanino said Prince Akishino is well known in Japan for his keen interest in Thailand. "He is a frequent visitor. He adores Thai cuisine and loves Thai culture."

Relations between the two countries can be traced back more than 600 years.

Sopaporn Kurz

The Nation