Iranian Oil Minister Bijan Zanganeh said CNPC was dragging its feet at what he said is a field with estimated reserves of more than 40 billion barrels of oil.
"There are problems with regards to progress," he said Wednesday.
Iran has tried to bring new foreign investors into the energy sector since brokering an interim nuclear deal in November that brought modest relief from sanctions. Sanctions on Iran's energy sector remain in place, however, and the U.S. Treasury Department issued new sanctions Tuesday for individuals suspected of trying to evade restrictive measures on Iran's oil sector.
The National Iranian Oil Co. signed a deal with its Chinese counterparts in 2009. The National Iranian Oil Co. was tasked by Zanganeh with finding a new contract to develop an oil field that straddles the Iranian border with Iraq.
Chinese companies are working with Iran to help develop the South Pars gas field in the Persian Gulf.