UNITED NATIONS — Iran's foreign minister invited the United States and other members of the UN Security Council to dinner Thursday night, his nation's latest high-profile attempt to avert more economic sanctions over its nuclear program.Western diplomats called it a rare move for a visiting dignitary such as Iranian Foreign Minister Manouchehr Mottaki to host a dinner for all the council's 15 member nations.Diplomats in most cases said before the 2-hour event that they would be sending a senior official, not the top-ranking ambassador. However, many nations did indeed send their top-ranking ambassadors, some notable exceptions being the US, Britain, France and Russia.Japan's UN Ambassador Yukio Takasu said after the dinner that Mottaki insisted Iran has the right to pursue nuclear energy capabilities for peaceful purposes."We were not here to negotiate but we had a very frank exchange of ideas which was meaningful," he said. "Iran should pursue more support from the international community. We want Iran to work harder."The occasion served as one of the highest-ranking contacts in recent years between the US and Iran, which lack formal relations.A spokesman for Iran's UN mission, M. Bak Sahraei, told The Associated Press the dinner was called "on the sidelines of (the) NPT review conference in New York." A monthlong conference reviewing the Nuclear Nonproliferation Treaty is under way at the United Nations.The dinner coincided with Thursday's launch of a billboard campaign by an advocacy group, United Against Nuclear Iran, which put up images in Times Square and Grand Central Station arguing no venue in New York should host the Iranians. The group is led by a former US representative for UN management and reform in the previous Bush administration.The US and some of its allies have argued that another round of sanctions is necessary to stop Iran's nuclear program, which they contend is aimed at producing a bomb. Iran says its program is for peaceful purposes.Sahraei noted that Mottaki also "is holding several meetings with the heads of foreign delegations" on the sidelines of the NPT review conference, including nonaligned nations and Security Council member nations.Invited nations had said they expected the obvious: A continuation of President Mahmoud Ahmadinejad's offensive earlier this week against new economic and military sanctions.Ahmadinejad, the only head of state to attend the NPT conference that opened at UN headquarters this past week, has been arguing that US-Iran relations might never be repaired if new sanctions are imposed.He also has campaigned by paying visits to Security Council member countries such as China, Russia, Brazil and Uganda in recent months.But a US official, who described the dinner at Iran's UN Ambassador Mohammad Khazaee's residence as "unusual," said before the dinner began that Wolff would attend in hopes of hearing something new."We see it as an opportunity for Iran to show the council that they're prepared to play by the rules and meet their international obligations," said the US official, speaking on condition of anonymity because of the sensitivity of the diplomatic situation.The council's five permanent members — the US, China, Russia, Britain and France — along with Germany have been holding talks on possible new sanctions against Iran for refusing to negotiate on its nuclear program.Russia and China still hope diplomacy will lead Iran to the negotiating table, and have indicated they will only agree to much weaker measures if Teheran refuses.Lebanon's ambassador holds the council's rotating presidency this month. The council's other nonpermanent members are Austria, Bosnia, Brazil, Gabon, Japan, Mexico, Nigeria, Turkey and Uganda.