US Secretary of State John Kerry on Wednesday extended exemptions from Washington's sanctions on Iran for nine economies.

Kerry said in a written statement that the nine economies, including China, India, Malaysia, South Korea, Singapore, South Africa, Sri Lanka, Turkey, and Taiwan, are qualified for the exemptions because their significant reductions in oil imports from Iran.

The exemptions will be valid for 180 days, according to Kerry. These economies were previously granted six months of exemptions in December.

"Today's determination is another example of the international community's strong and steady commitment to convince Iran to meet its international obligations," the chief US diplomat said.

He urged Tehran to take concrete actions to address the concerns of the international community, warning that otherwise it will face "increasing isolation and pressure."

The United States has 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 major breakthrough has been achieved.