Chinese Premier Li Keqiang praised the work of those searching for missing passengers in the Yangtze River after Monday's fatal accident, and urged local authorities to ensure their well being.

Li made the remarks on Wedesday morning at the site where he is leading rescue work. Strong rain and wind is hampering the efforts of personnel, including divers who continued to dive underwater through the night.

"The search and rescue mission is very physically demanding, and providing high-nutrition, high-energy food for the rescuers is of utmost importance so that they can re-energize and redouble their efforts," Li said.

"As long as there is the slightest hope, we must go all-out to find the missing. It's our obligation," he added.

The Eastern Star disaster could become China's deadliest shipping accident in almost seven decades. Over 450 people were onboard the ship when it sank after being hit by a tornado in Jianli, Hubei Province.

Rescuers have only found 14 survivors, and 26 bodies, leaving over 400 people still unaccounted for.

While visiting members of the dive team, Li asked how they were feeling and what the conditions were like underwater, adding that they have brought hope for those missing.

"Your skills are integral to this mission, and the public have huge expectations of you. The burden on your shoulders is heavy," Li told divers, urging them to be mindful of their own safety while racing against the clock to comb the ship.

According to government and army representatives at the site, the country's best divers, search and rescue experts, and equipment are involved in the mission.

Li called for "coordinated, scientific and pertinent" use of the equipment that had been rushed to the site overnight.

He expressed gratitude to everyone involved for their "devoted, continuous" effort.