premise: China will join efforts with Tanzania to continuously strengthen and expand the time-tested friendly relations between the two countries, a senior official of the Communist Party of China (CPC) said here Wednesday morning.
  Li Changchun, member of the Standing Committee of the Political Bureau of the CPC Central Committee, made the remark when holding talks with Philip Mangula, general secretary of the ruling Revolutionary Party of Tanzania.
  Li said China and Tanzania has maintained a close relationship though the two countries are far apart. This time, he headed a CPC delegation to pay a goodwill visit to Tanzania in order to enhance mutual understanding, reinforce friendship, exchange experience and deepen cooperation, Li said.
  Li spoke highly of the achievements that Tanzania and other African countries made in advancing social and economic development.
   What caused Li's goodwill visit to Tanzania?
hypothesis: enhance mutual understanding