The United States wants quick action to punish Iran for refusing to roll back its disputed nuclear program, and a new report by the UN nuclear agency strengthens the case for additional sanctions, US Secretary of State Condoleezza Rice said Friday. The United Nations "has a very strong case" for passing a third Security Council resolution imposing sanctions on Iran after the new report from the International Atomic Energy Agency found that Teheran failed to cooperate fully with its investigators and left unanswered crucial questions about its nuclear past, Rice said. "There is very good reason after this report to proceed to the third Security Council resolution," Rice told reporters at the State Department. "This report demonstrates that whatever the Iranians may be doing to try to clean up some elements of the past, it is inadequate, given their current activities, given questions about their past activities and given what we all have to worry about, which is a future in which Iran could start to perfect the technologies that could lead to nuclear weapons," she said. Rice spoke ahead of a meeting among senior diplomats from the five permanent members of the Security Council and Germany to discuss the new resolution, scheduled Monday in Washington. The six have agreed on a draft. Undersecretary of State Nicholas Burns, the third-ranking US diplomat, will represent the United States at the meeting. He said Friday there is "all the more reason now for the Security Council to pass a third sanctions resolution." The United States wants the Security Council to begin debate next week. Burns would not predict how long debate would last and would not rule out that the current package of proposed punishments might change. The proposed package slightly expands and strengthens previous penalties but is weaker than the United States had wanted. Britain and France introduced a council resolution on Thursday - with support from the United States, Russia, China and Germany - to expand and toughen travel bans and the freezing of assets for more Iranian officials linked to the nuclear effort. For the first time it would also ban trade with Iran in so-called dual-use items, those with both nuclear and other applications, and authorize inspections of shipments to and from Iran that are suspected of carrying prohibited goods. US Ambassador to the UN Zalmay Khalilzad said Friday that the Iranians were "increasing their capabilities. Not only have the number of centrifuges increased, but they're working on a second-generation, if you like, a more capable centrifuge...things are getting worse in terms of the enrichment part." Meeting with reporters over lunch at a Manhattan hotel, Khalilzad said the major Security Council powers planned early next week to discuss the resolution with four council members that have expressed reservations about further Iran sanctions - Libya, Vietnam, South Africa and Indonesia. Sounding confident of approval, he said a vote would be scheduled for next Friday. He said he believed "some were hoping the IAEA report would eliminate the need for the next resolution" - by assessing Iranian cooperation with the UN nuclear watchdog more positively. "The IAEA report does give us very important points to make," Khalilzad said. "They (Iran) did not come clean." He was referring to Teheran's dismissal of information supplied by the US and its allies said to show Iranian work on a missile re-entry vehicle, high explosives testing and conversion of uranium compounds, all of which might indicate nuclear weapons development. The Iranians rejected the purported evidence as fabrications.