WASHINGTON – US lawmakers are working on a set of new and unprecedented Iran sanctions that could prevent it from doing business with most of the world until it agrees to international constraints on its nuclear program, officials say. The bipartisan financial and trade restrictions amount to a “complete sanctions regime” against Tehran, according to one congressional aide involved in the process. But it could put the Obama administration in a difficult position with allies who are still trading with Iran, but whom the US needs if it is to secure a peaceful solution to the Iranian nuclear standoff. On Thursday, in its first foreign policy announcement since the president's re-election, the administration targeted four Iranian officials and five organizations with sanctions for jamming satellite broadcasts and blocking Internet access for Iranian citizens. But the measures that Senators Mark Kirk and Robert Menendez want to attach to a defense bill would be far more sweeping. They would target everything from Iranian assets overseas to all foreign goods that the country imports, building on the tough sanctions package against Tehran's oil industry that the two lawmakers pushed through earlier this year, congressional aides and people involved in the process said. Those earlier measures already have cut Iran's petroleum exports in half and hobbled its economy. Yet even as the value of its currency has dropped precipitously against the dollar in a year, sparking an economic depression and massive public discontent, Iran's leadership has yet to bite on an offer from world powers for an easing of sanctions in exchange for several compromises over its nuclear program. To break the logjam, the administration is brainstorming ways to make the offer more attractive for the Iranians without granting any new concessions that would reward the regime for its intransigence, according to administration officials who spoke on condition of anonymity because they weren't authorized to speak publicly on the matter. Escalating the sanctions, the measure's supporters say, could accelerate the point to which the Iranian economy is bankrupt, forcing Ayatollah Ali Khamenei to give ground in the nuclear negotiations. Supporters say they hope Iran's oil-inflated foreign currency reserves are depleted before it has the capacity to produce nuclear weapons-grade material, which Israel and others say could be as soon as August 2013. The United States and other world powers have been trying to gauge whether a negotiated solution is possible with Iran. Washington and many of its European and Arab partners fear Iran is trying to develop nuclear warheads, even if Iran insists that the program is solely designed for peaceful energy and medical research purposes. The Obama administration says military options should only be a last resort and has pressed Israel to hold off on any plans for a pre-emptive strike against Iran's nuclear facilities. But tensions between the US and Iran remain high, a fact underlined by the Pentagon's revelation Thursday that an Iranian military plane fired on, but missed, an unarmed US drone aircraft a week ago. The incident occurred in international airspace over the Arabian Gulf, Pentagon spokesman George Little said. A prominent Iranian parliament member said Friday that the drone violated Iran's airspace a week ago, when the Pentagon says it was fired on. The US maintains the pilotless craft was over international waters. – AP