U.S. Secretary of State John Kerry on Sunday said the window for diplomacy with Iran was "cracking open", AFP reports.
"Right now, the window for diplomacy is cracking open," Kerry told the American Israel Public Affairs Committee (AIPAC) summit in Washington via satellite from London, where he had met earlier with the EU’s foreign policy chief Catherine Ashton.
"But I want you to know that our eyes are open, too," he added. "When we say that Iran must live up to its international responsibilities on its nuclear program, we mean it.
"When President Obama says that he will not allow a nuclear-armed Iran, he means what he says. I believe firmly that no deal is better than a bad deal,” said Kerry.
"While we seek a peaceful resolution to Iran's nuclear program, words must be matched with actions. In any engagement with Iran, we are mindful of Israel's security needs,” he added.
The remarks come ahead of a meeting between Iran and world powers on Iran’s nuclear program.
The two-day talks kick off in Geneva on Tuesday amid raised hopes of a less hardline approach from the Islamic republic's new president, Hassan Rouhani, a reputed moderate who took office in August.
Since being elected, Rouhani has urged the world to seize the opportunity of his election to resolve the nuclear dispute.
Iranian Foreign Minister Mohammad Javad Zarif will negotiate with Ashton and the so-called P5+1 group of the United States, Britain, China, France and Russia plus Germany.
According to a Wall Street Journal report last week, Iran has prepared a set of proposals that it will take to the meeting in Geneva.
As an opening position in negotiations with the P5+1 group, the newspaper has said Tehran will offer to stop enriching uranium to levels of 20% purity, a level considered close to that needed to make nuclear weapons.