LHASA - A top official of Southwest China's Tibet autonomous region has vowed to put environmental protection first to protect the world's last "pure land".

Chen Quanguo, secretary of the Tibet Autonomous Regional Committee of the Communist Party of China, said environmental construction should be the heart of Tibet's development in a bid to protect the region's forests, grasslands, mountains and rivers.

Projects with high energy consumption, pollution and emissions will be strictly banned and mineral resource development will undergo environmental assessment procedures, he added.

Currently, all important construction projects in the region will undergo environmental impact assessments.

Last year, the region's water, air and soil maintained good quality and no major pollution incidents occurred. Tibet remains one of the areas with the best environmental quality in the world.

By the end of 2012, the region had 47 nature reserves with a total area of 410,000 square km, according to the regional environmental protection department.