Chinese Vice Premier Zhang Dejiang will pay an official visit to Pakistan, Sri Lanka, Greece and Austria from June 9 to 21, Foreign Ministry spokesman Qin Gang announced here Monday. Zhang will visit the four nations at the invitation of Pakistani Prime Minister Yousuf Raza Gilani, Prime Minister of Sri Lanka D.M. Jayaratne, Greek Deputy Prime Minister Theodores Pangalos and Austrian Vice Chancellor Josef Proll, said Qin. 