WASHINGTON (Agencies) The Obama Administrations nuclear posture review may have removed some of the intentional ambiguity from US nuclear policy, but it does not leave the country any less safe, US President Obamas top national security advisers said on CBS Face the Nation on Sunday. In fact, they said, it gives a clear warning to other state actors that the US will not ignore any growing threats. This is putting everybody on notice, US Secretary of State Hillary Clinton told CBS News chief Washington correspondent Bob Schieffer in an interview aired on Sunday. We dont want more countries to go down the path that North Korea and Iran are. The revised nuclear policy says that the US will not use nuclear weapons to respond to a chemical or biological attack from a non-nuclear country. The policy, however, leaves significant contingencies, said Secretary of Defence Robert Gates who also appeared on Face the Nation. Countries which are non-signatories to the Nuclear Non-Proliferation Treaty (such as North Korea) or have been found to be non-compliant (such as Iran) are not exempt from nuclear retaliation under the Obama policy. We were concerned about the biological weapons, Gates said, and thats why the President was very clear ... if we see states developing biological weapons that we begin to think endanger us or create serious concerns, that he reserves the right to revise this policy. Secretary of State Hillary Clinton said the US could not rule out using nuclear weapons if it came under biological attack, saying in that case all bets are off. If we can prove that a biological attack originated in a country that attacked us, then all bets are off, she said. Gates also pointed out that the policy dictates that any country that uses chemical or biological weapons against the US will suffer a devastating conventional retaliation. In spite of recent strained relations between Kabul and Washington, Gates and Hillary defended Afghan President Hamid Karzai as a valuable and reliable partner, despite tensions over his outspoken comments. Karzai had excellent relations with the head of US and Nato-led troops in Afghanistan, General Stanley McChrystal, Gates said. What I can tell you is that General McChrystal continues to meet with him regularly. They have a very positive relationship. He gets very good cooperation out of President Karzai, said Gates told ABCs This Week. Both Gates and Hillary expressed support and understanding for Karzai in the latest attempt by Washington and Kabul to repair a rift triggered by the Afghans presidents controversial outbursts. Karzai had accused foreign governments of orchestrating the fraud at last years elections that returned him to power, causing dismay in Washington. Gates, offering an explanation for Karzais recent angry tone, said Washington had to be careful in its public remarks about the Afghan President, as sharp criticism of his performance could be received in Kabul as disrespect for Afghan sovereignty. The US Defence Chief said when there are attacks on him (Karzai), on his family, and what he perceives to be on Afghanistan itself, or insults to the sovereignty of Afghanistan, hes going to react. And hes going to react strongly. Hillary said Karzai, like some other foreign leaders, suspects harsh words in American newspapers may reflect the US governments official stance. She further said she had a lot of sympathy for President Karzai and the extraordinary stress he lives under every single minute of every day. Gates said Karzai is playing a key role in military efforts to win control of Kandahar, the birthplace of the Taliban, by talking with tribal leaders and local officials to get their views and concerns. Hillary said the US has reached out to Russia for cooperation in its missile defence programme. We would like to see a joint effort on missile defence because we dont see the principle threat in nuclear terms coming from Russia, we see it coming from state actors like Iran or non- state actors like a terrorist organisation like Al-Qaeda getting a hold of nuclear materials, she said. The Pentagon chief said Iran is not on the threshold of producing a nuclear weapon and that its programme was progressing slower than Tehran expected. Id just say, and its our judgment here, they are not nuclear capable, Gates said in the interview. Not yet. He said Iran was continuing to make progress in a nuclear programme that Washington suspects is a clandestine effort to develop an atomic arsenal. Its going slower... than they anticipated. But they are moving in that direction, he said. The Pentagon chief also denied that the US administration was resigned to Iran becoming a nuclear-armed power. We have not... drawn that conclusion at all. And in fact, were doing everything we can to try and keep Iran from developing nuclear weapons, he said. Secretary of State Hillary Clinton argued that Washingtons patience had helped build international support for sanctions against Iran. She told NBC that what we have found over the last months, because of our strategic patience, and our willingness to keep on this issue, is that countries are finally saying, 'You know, I kind of get it ... theyre the ones who shut the door, and now we have to do something.