China has slowed oil and gas investments in Iran in efforts to ease tension with the Obama administration and avoid US sanctions on its big energy companies, drawing anger from Tehran, Reuters reported. “Whatever we do in Iran, the Americans are watching,” said a senior Chinese oil executive and a Beijing-based researcher. China has been one of the only countries willing to provide the billions of dollars of energy investments for Iran’s strategic oil capacity maintenance, but the relationship is fraying. The Iranian government has already twice warned CNPC – China’s largest energy group – to speed up work on the South Pars gas field in Iran or risk losing the contract. China National Offshore Oil Company (CNOOC; CEO.NYSE) was told by Beijing to pull its team from the South Pars field, according to an anonymous government source, and Sinopec (SNP.NYSE) has delayed the start date of the US$2 billion Yadavaran oil development project.