Israel expects that a fourth round of UN sanctions against Iran likely won't be in place until the beginning of 2009, but that further unilateral US and EU measures could be imposed as early as next month. The assessment comes as the five permanent UN Security Council members and Germany threatened further sanctions against Iran, failing an agreement to negotiate over its nuclear program and suspend its enrichment of uranium. Iran has said it would offer its formal response Tuesday to the latest incentive package offered by the six nations - the US, France, England, China, Russia and Germany - to start the negotiating process. European and American diplomats were still reviewing the document at press time, but a US official told the Associated Press that it was "more obfuscation and delay" and not a "real response" to the offer. "We are looking for a clear, positive response from Iran, and in the absence of that, we're going to have no choice but to pursue further measures against them," said State Department spokesman Gonzalo Gallegos. Accordingly the six nations will hold a conference call Wednesday about the next steps to be taken. State Department and Treasury spokesmen wouldn't offer details on what a future sanctions resolution might entail. Israeli sources, however, indicated that they expected a UNSC resolution similar to the previous three that were approved, which sanctioned certain individuals and companies but were limited in scope. "They're not aiming for a robust resolution. They want [to show] that the international community is united," said one Israeli official. "Even if it will take more time than this administration has, it's important to start the process." The official said he "wasn't that optimistic" that even a weak resolution would pass by the end of the year. He pointed to the August holiday season in Europe followed by the opening of the UN General Assembly at the end of September, followed by the intensification of the American election campaign. He warned that by the beginning of 2009, Iran could make major strides toward producing nuclear weapons, but that a "multi-track" approach would send an important signal to Iran while unilateral measures would send a tougher message still. Among those under consideration are designations of further Iranian individuals and financial entities as the US government has done in the past, as well as an expanded push by the US Treasury to make insurance companies rethink the cost of doing business with Teheran, as it has successfully encouraged major financial institutions to do. There is also interest in disrupting shipping to Iran, which could also affect the country's energy supplies. Backers of this strategy pointed to StatoilHydro's decision not to undertake new business in Iran as a sign of its success. The state-owned Norwegian energy giant announced the move last week, the latest in a string of similar decisions by major multinational energy companies. Israel, the US and increasingly the EU have seen such pressure outside the framework of the UN as having a greater chance of success at affecting Iran's behavior. Russia and China have been reluctant to impose harsh UN sanctions, and the lack of a clear-cut Iranian reaction to the six nations is likely to drag the diplomatic wrangling out further. "It puts the [six nations] in a very difficult situation because it's not a secret that there are those among the [six] who believe that the diplomatic option should be exhausted before sanctions and other measures [are used]," said the Israeli official, who indicated that this aided Teheran's designs. "The overall Iranian strategy is simply playing for time. They are waiting for the elections here in the USA. They believe the next administration will give them a better deal."