US Secretary of State Hillary Clinton implicitly warned Iran on Saturday not to interfere in neighbouring Iraq after President Barack Obama announced all US troops will leave Iraq by year end. "As we open this new chapter in a relationship with a sovereign Iraq, to the Iraqis we say: 'America is with you as you take your next steps in your journey to secure your democracy," Clinton said on a visit to Tajikistan. "And to countries in the region, especially Iraq's neighbours, we want to emphasise that America will stand with our allies and friends, including Iraq, in defence of our common security and interests," she said.