Chinese President Xi Jinping on Friday sent letters of sincere greetings to 25 representatives of scientific and technological workers, including Yuan Longping, Zhong Nanshan and Ye Peijian, on the occasion of the fourth National Science and Technological Workers' Day.

President Xi encouraged scientists and technologists across the country to conquer key and core technologies and make new and greater contributions to building China into a world power in science and technology.

Calling innovation the primary driving force of development, Xi said Chinese scientists have made great contributions in the fight against COVID-19. 

They've worked round the clock to develop drugs and vaccines, helping save lives both at labs and on the front line.

Xi noted that the circumstances, challenges and missions are pressing, calling scientists to lead future development direction, shoulder heavy responsibilities bestowed by history, and be vanguards in innovation in the new era.