President Hu Jintao has decided to cut short his planned tour of key South American nations and head home early after the BRIC summit in Brazil, in order to help better direct disaster relief after a 7.1-magnitude quake struck Qinghai early Wednesday.

Hu will postpone his scheduled visit to Venezuela and Chile, which was slated for Saturday and Monday.

The delegation arrived in Brazil on Tuesday. Hu is scheduled to meet Indian Prime Minister Manmohan Singh and Russian President Dmitry Medvedev on Thursday, and attend the BRIC summit the next day, before leaving to Beijing.

Hu phoned Chilean President Sebastian Pinera and Venezuelan President Hugo Chavez to explain his change in schedule.

"At this difficult time, I need to return to China as soon as possible and join the people in disaster relief," Hu told the two leaders.

Pinera expressed his full understanding and support for Hu's decision. He also expressed deep condolence for quake victims in Qinghai.

Chavez also said he fully understand Hu's decision, and expressed his deepest condolence. Chavez said Venezuela wishes to offer all necessary support for China's post-quake disaster relief.

Premier Wen Jiabao has also decided to postpone his visit to Brunei, Indonesia, and Myanmar, scheduled for April 22-5.

The death toll from the quake in northwest China's Qinghai Province has risen to 617, rescuers said Thursday.

The latest statistics show that 313 people were missing and 9,110 injured, 970 severely, said a spokesman with the rescue headquarters in the Tibetan Autonomous Prefecture of Yushu in southern Qinghai.