German Chancellor Angela Merkel said that heading off the prospect of a nuclear-armed Iran, with tougher sanctions if needed, remains a "vital interest" for the world community, according to a report Thursday. Iran's nuclear program is "one of our biggest security policy concerns," Merkel wrote in an article for the daily Handelsblatt, which the newspaper posted on its Web site ahead of print publication on Friday. Germany, along with the five permanent members of the UN Security Council, has played a leading role in addressing worries over Iran's nuclear ambitions. Earlier this month, an American push for new sanctions was dampened with the release of a new US intelligence report concluding Iran had halted a nuclear weapons development program in 2003 and had not resumed it since. Merkel did not refer specifically to that assessment, but wrote that "it is dangerous and still grounds for great concern that Iran, in the face of the UN Security Council's resolutions, continues to refuse to suspend uranium enrichment," Handelsblatt reported. "The Iranian president's intolerable agitation against Israel also speaks volumes," she was quoted as saying. "It remains a vital interest of the whole world community to prevent a nuclear-armed Iran - if necessary, with the further toughening of sanctions." "We will continue to work with our partners, with determination and patience, on a diplomatic solution," Merkel said.