The Obama Administration also said Iran's controversial atomic programme cannot be a situation of "business as usual" since it is about the danger of a nuclear arms race in the Middle East, which will have its implications outside the Middle East including India.
"From our standpoint and what we have made clear in our conversations with many countries, is that this (Iran pursuing the path of nuclear weapons programme) cannot be a situation of business as usual," State Department spokesman P J Crowley told reporters.
"This is about the future of the world. This is about the danger of a nuclear arms race in the Middle East, which will affect countries outside of the region, including India.
So everyone has a responsibility to do what each country can to convince Iran to change its present course," the State Department spokesman P J Crowley said.
When asked about the recently held India-Iran Joint Commission in New Delhi last week, "I'll leave it to India to describe what steps it is going to take."
To a query on specific comments made by Foreign Secretary Nirupama Rao about the latest round of US sanctions against Iran, Crowley said he is not familiar with those particular comments. Rao had said such "unilateral sanctions" can have "a direct and adverse impact" on India's energy security.
But Crowley said, "Every country obviously pursues its own self-interest of its citizens. We understand that. By the same token, all countries have international obligations to fully respect and to heed the sanctions that were passed by the Security Council last month."
"We are taking our own steps to fully implement those sanctions and to take additional steps within our own laws. And we would expect all countries to respect and commit themselves to undertake and to enforce the sanctions that have been passed by the UN Security Council," Crowley said.
"We have ongoing concerns about the nature of Iran's nuclear programme. There are many questions that we have that have gone unanswered.
"You even have today concerns expressed by (Russian) President (Dmitry) Medvedev, which we share, about Iran continuing to move closer to having a breakout nuclear capability.
It is up to Iran to come forward and engage the IAEA and the international community constructively. Iran has failed to do that," he said.
The State Department spokesman said US is moving forward both to implement international sanctions and to evaluate how they can take additional national measures that puts pressure on the Iranian Government to come forward and engage constructively.