LHASA -- Tibet has a huge task ahead to reduce by 690,000 the number of people living below the poverty line by 2020, regional poverty relief officials said ahead of the annual meeting of the Tibetan Regional People's Congress, the local legislature.

During the last five years (2011-2015), Tibet lifted more than 600,000 people out of poverty, said Gou Ling, Communist Party of China (CPC) secretary of Tibet Autonomous Region poverty relief office.

However, the plateau environment, which is prone to natural disasters, has posed a challenge to poverty alleviation, Gou said. Disease is also a major factor that is holding back development.

About 74 percent of the impoverished population live in Xigaze, Qamdo and Nagqu prefectures, large swathes across the western and eastern parts of the region.

"The next five years will be the greatest task of all," said Gou.

Tibet plans to focus policy on welfare for poor people, job creation and relocation packages, he added.