US officials say Russia can take part in Nabucco gas pipeline project but not Iran. The United States says it does not object to Russia''s participation in a pipeline project to bring gas to Europe but claims Iran should be excluded until it improves its ties with the West. Richard Morningstar, U.S. special envoy for Eurasian energy issues, says the U.S. is trying to engage with Russia on energy issues. Senator Dick Lugar says Russia could take part as a customer or a supplier.

Morningstar, however, says Iran should be left out of the project until it improves its ties with Europe and the U.S. Washington has reached out to Iran but has not so far received a "positive response," he says.

The 3,300 kilometer (2050 mile) pipeline will bring Caspian and Central Asian gas to Europe to reduce EU dependence on Russian natural gas.