Russian oil company Lukoil said Wednesday it reopened its offices in Iran in anticipation of the full removal of economic sanctions.

Lukoil started work in the Anaran reserve area near the border with Iraq in 2003, but was later forced to pull out of Iran as sanctions tightened. Lukoil Deputy Vice President Ravil Maganov said the company was back in Iran.

"We look forward to participation in projects in Iran after the sanctions are fully removed", he said. "We are studying geological data on other projects as well."

The director of Iran's National Petroleum Co. last week said foreign investors "will flock to Iran" if a framework nuclear agreement brokered with the help of Russia and other members of the U.N. Security Council, plus Germany, takes force in July.

The April 2 framework is still under review. A U.S. Senate committee voted in favor of a controversial measure that would give Congress power to weigh in on any formal deal.

"This bill always has been about allowing Congress the opportunity to review any final deal to ensure it is verifiable and enforceable before the president could act to unwind the sanctions that Congress put in place and which brought Iran to the table," U.S. Sen. Bob Corker, R-Tenn., chairman of the Senate Foreign Relations Committee, said in a statement.

Iran, for its part, has reached out to Russia since the framework agreement was reached. Both sides this week revisited a deal for the S-300 missile defense system, which the Kremlin shelved in 2010 because of sanctions against Iran.

Iran is limited to around 1 million barrels of oil per day in exports under the terms of a November 2013 deal with international powers. Exports could double if all sanctions are released later this year.