From tough new sanctions against North Korea to a sweeping strategy aimed at eliminating nuclear weapons, the US ambassador to the United Nations says US President Barack Obama's promise to work with other countries is yielding results. Nearly a year after becoming the top US diplomat to the global body, Susan Rice said in an interview this week with The Associated Press and AP Television News that challenges remain, though she sees evidence every day "that the world is responding differently and much more openly to the United States of America." Many nations felt that former president George W. Bush's administration did not have a strong commitment to working with other countries, and they complained that US power as the world's richest nation and a veto-wielding member of the UN Security Council was disproportionate. At the UN General Assembly in September, Obama told world leaders the United States would reach out in "a new era of engagement based on mutual interest and mutual respect." And he challenged leaders from the 191 other UN member states to share the burden, saying America couldn't solve the world's problems alone. Rice, who was Obama's top foreign policy adviser during the presidential campaign, said the United Nations is crucial to carrying out this key foreign policy objective. "The change in the nature and tone of our relationships ... is yielding concrete and tangible benefits here at the United Nations - benefits that advance US interests," Rice said. She pointed to the Security Council's approval in June of tough new sanctions against North Korea following its second nuclear test. Veto-wielding council members Russia and China, and sanctions-wary Libya joined in the unanimous vote for the sanctions. "They have been actively and forcibly implemented by member states all over the world," Rice said. "So North Korea is feeling far greater pressure to halt its nuclear weapons program than it has in the past, and it is indeed giving various indications that it is feeling that pressure and perhaps responding to it." She did not elaborate on how they were responding. Rice also singled out Obama chairing the Security Council in September - a first for a US president at a summit of the UN's most powerful body - when it unanimously adopted a US-sponsored resolution aimed at halting the spread of nuclear weapons and ultimately eliminating them. She called it "a very significant commitment" by leaders of the 15 council nations which "accelerated and embraced the president's goal of attaining a world without nuclear weapons." Rice cited two other US accomplishments this year - a resolution condemning sexual violence in war zones and strengthening the legal foundation to protect women and girls from attacks, and a resolution adopted last week revamping al-Qaida and Taliban sanctions to ensure that sanctions only target those individuals, companies and organizations linked to the terror groups. She said the United State has made progress on these important issues in partnership not only with countries that are traditionally friendly to the US but with some countries that Washington has had "more difficult dealings" in the past. In addition to her UN job, Rice is a member of Obama's Cabinet and sits on the National Security Council. She said she spends 4-5 days in New York and does a lot of work by videoconference, but she tries to work Fridays in Washington, where her husband and two children live. She also has traveled on behalf of the administration, representing Obama at a conference in Israel in October and joining the president in China in November. As a former assistant secretary of state for African affairs in the Clinton administration, Rice came to the Security Council - which spends about 60 percent of its time on African problems - with deep knowledge of the continent's problems and promise. She has strongly advocated the protection of civilians, especially in Darfur and Congo, against attacks and rapes. Looking ahead to 2010, the question of what to do about Iran's nuclear program looms large. On Tuesday, Iran's President Mahmoud Ahmadinejad dismissed a year-end deadline set by the Obama administration and the West for Tehran to accept a UN-drafted deal to swap enriched uranium for nuclear fuel. Rice said Iran has a choice between engagement or increased pressure, which could include new sanctions. "In the new year, absent some significant changes in the posture of Iran, I think we believe that the time will be ripe for serious consideration of additional pressures," she said. But she said the United States will also have to deal with many other challenges next year. The US is preparing for a major conference at UN headquarters in May to review the Nuclear Nonproliferation Treaty (NPT). The United States will also be trying to promote a peace settlement in Darfur and ensure that preparations move ahead for a referendum in 2011 on independence for South Sudan. And it will continue focusing on trying to prevent waste, fraud and abuse at the United Nations, she said.