BEIJING - President Xi Jinping on Sunday offered his condolences over the death of Chinese nationals and ordered the Chinese diplomatic missions to make all-out efforts to help the survivors of a crash landing of a Republic of Korea (ROK) passenger plane at a San Francisco airport.

Xi mourned for Chinese citizens who lost their lives in the plane crash and expressed his condolences to their families as well survivors of the crash, said a release from the Chinese Foreign Ministry.

Xi has also ordered the foreign ministry, the Chinese embassy in the United States, the Chinese Consulate General in San Francisco and the Chinese embassy in the ROK to make all-out efforts to provide assistance to the injured and the other Chinese survivors, said the release.

Two Chinese nationals were killed in the crash, the Chinese Consulate General in San Francisco confirmed Saturday night.

A total of 141 Chinese citizens were among the 291 passengers aboard the Asiana Airlines Boeing 777-200, which originated in Shanghai and picked up passengers in the ROK before heading to San Francisco.

Some 182 people were injured and have been sent to nine hospitals near the airport. Forty-eight people remain in serious condition, San Francisco Mayor Ed Lee told reporters Saturday night.

Xi has ordered the Chinese foreign ministry, embassies and Consulate General in San Francisco to keep in touch with the US side and the ROK side to appropriately address issues in the wake of the crash, said the release.

Chinese Foreign Ministry Spokesman Qin Gang told reporters that 78 of the Chinese passengers have been confirmed safe as of 19:00 Beijing Time (11:00 GMT) and the Chinese Consulate General in San Francisco is trying to get more information about all the others.

The US side and the ROK side have pledged to provide all necessary convenience and assistance to the Chinese side, said the spokesman.