Japan's Emperor Naruhito and Empress Masako have appeared online at an opening ceremony of the World Conference on Earthquake Engineering.
The conference, held every four years, began in Japan's northeastern city of Sendai on Tuesday. About 3,000 experts on earthquake engineering and disaster prevention took part, mainly online from around 80 countries and regions.
At the ceremony, the emperor gave a speech in English from the residence at the Imperial Palace in Tokyo.
He offered words of condolence to the victims of the 2011 Great East Japan Earthquake, which triggered massive tsunamis, and heartfelt sympathy to people affected by the disaster.
He also thanked those working for reconstruction and recovery of affected regions.
The emperor said he hopes the conference will become an important chance to significantly reduce the damage from earthquakes and tsunamis. He said this can be done by bringing together experts in earthquake engineering and disaster management to share research outcomes as well as past disaster experiences and lessons leant.
The emperor and empress are known for supporting people in the disaster-hit areas and learning about earthquake damage. They appeared to listen attentively to the experts' lectures.