Chinas state oil company has pulled out of a $5 billion deal to develop a portion of Irans massive offshore natural gas field, Irans oil minister said Sunday. The South Pars field deal, struck in the wake of Irans 2015 nuclear deal with world powers, appears to be just the latest business casualty of USs pressure campaign on Tehran following President Donald Trumps unilateral withdrawal of the US from the deal. Oil Minister Bijan Zangeneh, quoted by the ministrys SHANA news agency, said Sunday that the China National Petroleum Corp. was "no longer in the project," the Associated Press reported. He did not elaborate or give any reason for the withdrawal, though SHANA said the company "had pulled out of a contract" to develop the field. Officials in Beijing didnt immediately acknowledge their decision. Meanwhile, Iranian Foreign Minister Mohammad Javad Zarif complained Sunday about the US campaign against Tehran and its impact on foreign investments. "We have been facing plenty of problems in the field of investment because of the US maximum pressure policy," Zarif told a parliamentary committee, according to the semi-official Tasnim news agency. "We are trying to remove the problems," he added.