U.S. Secretary of State John Kerry told reporters on Saturday that "important gaps" still remain between Iran and six world powers attempting to negotiate limits on Iran's nuclear power program, Reuters reports.
"I can't tell you whether or not we can get a deal, whether we are close," Kerry said. "The purpose of these negotiations is not just to get a deal, it is to get the right deal."
The United States, along with Britain, Germany, France, China, and Russia, will resume talks with Iran on Sunday. The two sides hope to reach an interim agreement by the end of March, and then negotiate a final deal by June 30. The six world powers want Iran to curb its nuclear programs, in exchange for an end to sanctions that have crippled Iran's economy.
Kerry also addressed a letter sent by U.S. Republican senators to Iran last week, which warned that any deal made would not outlast President Barack Obama's presidency.
"As far as we're concerned, Congress has no ability to change an executive agreement," Kerry said of the warning.