The United States on Wednesday urged the Iranian government to give a formal response to a UN-backed draft deal over its nuclear program, warning that Tehran's non-cooperation would lead to more pressure.

According to the deal, which was brokered by the International Atomic Energy Agency (IAEA), about 70 percent of Iran's enriched uranium would be shipped abroad in exchange for fuel rods for research use.

The deal was agreed by the other parties involved in negotiations with Tehran, including the United States, Russia and France.

"We've all accepted this proposal and have submitted a formal response to (IAEA Chief Mohammed) ElBaradei. And this is what Iran needs to do ... And that's what we're waiting for," said State Department spokesman Ian Kelly.

Iran's Foreign Minister Manouchehr Mottaki said on Wednesday that his country has already submitted its response on the deal to the IAEA, adding that Iran would consider a uranium-for-fuel swap inside the country.

"Until the IAEA gets the response and formally says this is Iran's response, I don't consider a statement to the press necessarily a response," said Kelly.

"We have a policy of a dual track, both engagement and pressure... At a certain point, ... we're not going to close any door on the engagement track, but at a certain point, we're going to start paying a little more attention to the other track," said the spokesman.

The United States, its European allies and Israel claim that Iran's nuclear program is aimed at developing nuclear weapons, while the UN Security Council also requires Iran to suspend its uranium enrichment activity.

However, Iran insists that its nuclear plan is only for peaceful purposes, and continues its uranium enrichment activity despite the pressure from the western countries and relevant resolutions and sanctions of the United Nations.