In a letter last week, a group of 47 Republican senators ignored protocol and sent an open letter to Iran’s leaders, warning that the Congress would ultimately walk away from any agreement Iran may reach with President Barack Obama.

The surprise letter, which elicited strong condemnation in the US, came as Iran and the P5+1 global power are engaged in intensive talks to reach a permanent accord on the Islamic Republic’s nuclear program.

“We know that the US oil companies are not happy with the letter of 47 senators against the nuclear talks,” Hosseini said.

Hosseini said oil companies flocked to Iraq “in a frenzied way” in 2005 after international sanctions against that country were lifted.

Iran and the P5+1 countries  are seeking to seal a comprehensive nuclear deal by July 1.The two sides have already missed two self-imposed deadlines for inking a final agreement since they signed an interim one in the Swiss city of Geneva in November 2013.

“The objective of the [planned] seminar is to introduce the new model of contracts and new opportunities for investment in Iran’s petroleum industry, but we have no option but to consider political aspects because economic issues are tied to the [issue of] sanctions,” he said.

The committee, led by Hosseini, has been modifying the terms of oil contracts in order to sweeten them for foreign companies. The new model, known as Iran Petroleum Contract (IPC), is replacing buyback deals.

But under the IPC, National Iranian Oil Company (NIOC) will set up joint ventures for crude oil and gas production with international companies which will be paid with a share of the output.