Iran is making good progress in talks with Royal Dutch Shell PLC (RDSB) and Repsol SA (REP) on a key production and liquefaction scheme called Persian LNG, an Iranian news agency said Wednesday, quoting a top official.

The statement comes as Iran is stepping up publicity around foreign oil talks amidst rising tensions with the West over its nuclear program. But years of negotiations with European companies have yet to yield any final deal.

"Negotiations with Shell and Repsol in recent weeks have gone in the desired direction and efforts are being made to take action as quickly as possible given the mutual interests in this field," Seifollah Jashnsaz, managing director of the National Iranian Oil Co., was quoted as saying by the ISNA agency.

The Persian LNG project consists in developing of the phases 13 and 14 of South Pars Gas field and the construction of two LNG trains each with a capacity of 8.1 million metric tons a year.

Shell didn't return a request for comment and Repsol couldn't be reached.

The statement comes after Iran said Monday that talks with France's Total SA (TOT) had resumed on South Pars phase 11, which is tied to the Pars LNG export scheme. Total has declined to comment.

Total, Shell and Repsol have so far refrained from signing final commitments to implement the projects, after coming under pressure from the U.S.

Due to U.S.-imposed sanctions, Iran has been unable to grow into a global gas power, despite holding the world's second-largest reserves.

Recently, Washington and its Western allies have called for even tougher sanctions unless Iran allays international concerns it is seeking nuclear weapons. Iran says its nuclear program is peaceful.

The tensions have already led to renewed pressure in the West against dealing with Iranian companies.

The U.K. government Monday ordered U.K. financial companies to stop trading with two Iranian firms, Bank Mellat and the Islamic Republic of Iran Shipping Lines and some European companies have quietly dropped their gasoline sales to Iran.

-By Benoit Faucon and Reza Amanat, Dow Jones Newswires; +44-20-7842-9266; benoit.faucon@dowjones.com