Though doors may be opening to the Iranian oil sector, the government in Tehran hasn't been in contact with any U.S. companies, a top official said Monday.

Iran aims to do away with buy-back contract offers, whereby the host country agrees to buy produced hydrocarbons at a set price, and replace them with joint venture projects in an effort to woo foreign companies back to the Iranian energy sector.

Mehdi Hosseni, the head of a contract revision committee in the Iranian Oil Ministry, said nearly a dozen new exploration and production projects are envisioned under the terms of a new contract regime under review.

Iran's oil minister in early March hosted multinational corporate representatives at a four-day energy conference in Tehran. Prior to the event, the Iranian government said it expected a U.S. presence at the event.

"We are in regular contacts with companies from Europe and Asia, but there has been no contact yet with American companies," Hosseni said Sunday.

Iranian oil production of 2.7 million barrels per day has remained relatively steady since 2013. Exports are limited by sanctions to around 1 million bpd and to only six other countries. Sanctions imposed on Iran's energy sector, however, could be lifted if a framework nuclear agreement is finalized this summer.

In a monthly review, the Organization of Petroleum Exporting Countries noted the Iranian government viewed its oil industry as "very attractive" to foreign investors, including those from the U.S. and European economies.

The U.S. State Department said sanctions are still in place on Iran. The country, a spokesman said, "is not open for business yet."