A state-owned Chinese bank that had agreed to finance the Pakistani section of a gas pipeline from Iran that is opposed by the United States is no longer interested in the project, a Pakistani finance ministry spokesman said Wednesday.

Finance Ministry spokesman Naveed Iqbal said he didn't know why the Industrial and Commercial Bank of China was apparently backing out, but said "the geopolitical situation" had previously been cited by the petroleum ministry as the reason.

The U.S. has warned Pakistan and companies assisting the project could face sanctions if they go ahead.

Washington believes Iran is trying to develop a nuclear bomb, and wants to isolate Tehran economically to try and get it to abandon any nuclear plans. Iran says its nuclear program is for peaceful purposes.

Iqbal said the Chinese bank and Pakistan's Habib Bank Limited had jointly agreed to help finance the Pakistani section of the pipeline, but now seemed to "have no more interest in the project." Neither company could immediately be reached for comment Wednesday.

Pakistani leaders have vowed to press ahead with the pipeline despite U.S. opposition, saying it was vital for the supply of gas to the energy-starved country. But there have been widely expressed doubts over who will finance the project given U.S. opposition.

Asked about the Chinese bank's apparent withdrawal, Pakistani Foreign Minister Hina Rabbani Khar said, "There are always a multiplicity of funding sources which are available for any project."

"This is a fairly viable project and we hope and we will not see any problem in trying to find ways and means of ensuring its funding," she said.