(CNN) Iran's Supreme Leader Ayatollah Ali Khamenei said Wednesday his country will react if the United States renews sanctions against the Islamic Republic.

"If this sanction is implemented, this is definitely a violation of the agreement, without any doubt," Khamenei said in an address on state television. "And they should know that the Islamic Republic will definitely react towards it."

The US Congress voted last week to extend the Iran Sanctions Act for another 10 years.

However, the Obama administration is working to stave off any additional sanctions and encouraging American companies to do business with Iran, a US official tells CNN.