The U.S. government announced on Friday that it is extending exemptions from its sanctions on Iran for nine economies, including China, India and the Republic of Korea (ROK).

In a written statement, U.S. Secretary of State Hillary Clinton announced that these economies have again qualified for the exemptions because they have made additional reductions in their oil imports from Iran.

These economies were previously granted six months of exemptions in June.

Clinton said that financial institutions based in these economies will be exempted from U.S. sanctions on engaging in transactions with Iran for a "potentially renewable period of 180 days."

According to the statement, a total of 20 economies have continued to significantly reduce their oil imports from Iran.

Citing the latest U.S. Energy Information Administration report to Congress, Clinton said that Iran's oil production fell by one million barrels per day in September and October of 2012, compared to the same period in 2011.

The sanctions have "reduced Iran's export volumes and oil revenues," a key funding source of its controversial nuclear program, the top U.S. diplomat claimed.

She urged Iran to "take concrete actions to satisfy the concerns of the international community through negotiations with the P5+1," adding that the Islamic republic would otherwise "face increasing isolation and pressure."

Major Western powers have long accused Tehran of secretly developing nuclear weapons, while Iran insists its nuclear program is for civilian purposes only. The P5+1 countries -- the five permanent members of the UN Security Council plus Germany, have held numerous rounds of negotiations with Iran in order to solve the logjam, but so far no substantial results have been achieved.