WASHINGTON - US President Barack Obama had three unique tasks to juggle on Thursday night, and only at the White House were they obviously interlinked.Around 8 o'clock, Obama wished his guests for the evening a happy holiday season— and reassured them that, at the end of yet another year in the long saga over Iran's nuclear program, his administration still stands committed to the security of the Jewish state.It was the second of two Hanukkah receptions in the building's grand foyer that night. Since the first, the president's role model, Nelson Mandela, had died."Together with our Israeli friends, we're determined to prevent Iran from obtaining a nuclear weapon," Obama said. "And we’re testing whether it's possible through diplomacy to achieve that goal, understanding that we have to remain vigilant."Late in November, the US and Russia, China, the United Kingdom, France and Germany successfully negotiated an interim deal with Iran that effectively halts its nuclear program for six months. Within that period, world powers hope to codify a solution to the Iranian nuclear crisis "once and for all," the president told the predominantly Jewish crowd."Key parts of the program will be rolled back, even though the toughest of our sanctions remain in place," the president continued. "And that’s good for the world and that's good for Israel."The White House justified two celebrations this year to accommodate over one thousand guests, including members of Congress, three Supreme Court justices, donors and family friends, television stars and Israeli and Jewish leaders."Over the coming months," he said, "we’re going to continue our diplomacy with the goal of achieving a comprehensive solution that deals with the threat of Iran’s nuclear weapons once and for all."News of Mandela's death broke suddenly between the two receptions, challenging the president to tie two seemingly foreign events to one another.The president gave a brief eulogy from the press briefing room before returning to the Oval Office."We will not likely see the likes of Nelson Mandela again," he said. "So it falls to us as best we can to forward the example that he set: to make decisions guided not by hate, but by love; to never discount the difference that one person can make; to strive for a future that is worthy of his sacrifice."At the second ceremony, Obama said that at the heart of Mandela's legacy is the moral imperative to fight for freedom— a core tenet of the story of Hanukkah, as well."The idea that every single human being ought to be free and that oppression can end and justice can prevail," Obama said, "That's what Nelson Mandela taught us, and it’s that same spirit that brings us here tonight."The menorah used in the first ceremony which occurred before sundown in the holiday's final hours featured branches fashioned to emulate the Statue of Liberty. The piece was designed by a Holocaust survivor in 1986, the centennial of the original statue's construction in New York.The second menorah, from the nineteenth century, was held in a Jewish prayer hall in the Czech Republic until the Nazis torched the building during World War II. The menorah survived, and now takes residence in the home of the US ambassador to Prague.Israel's new ambassador to the United States, Ron Dermer, attended the second ceremony. He turned in formal paperwork to the president earlier this week, officially becoming Israel's envoy to the US.The president will light the national Christmas Tree on Friday night.