WASHINGTON (Agencies) - It could be months before efforts to broker a peace deal between the Afghan government and the Taliban bear fruit, US Defence Secretary Robert Gates said in an interview aired on Sunday. Gates, who steps down at the end of the month, said there had been contacts between United States and the Taliban in recent weeks, headed by the State Department. Theres been outreach on the - on the part of a number of countries, including the United States. I would say that these contacts are very preliminary at this point, he told CNN. The comments from the outgoing US defence chief were aired a day after Afghan President Hamid Karzai announced the United States was in contact with the Taliban, a striking public acknowledgment of a peace initiative that has been cloaked with secrecy. Karzai said an Afghan push towards peace talks, after nearly a decade of war, had not yet reached a stage where the government and insurgents were meeting, but their representatives had been in touch. The comments come as President Barack Obama prepares to announce the size and nature of the initial US drawdown from Afghanistan nearly 10 years after the September 11 attacks. Obama, who has increased the size of the US force by about 65,000 soldiers since he took office in early 2009, is hoping to move definitively towards ending the war as he faces sharp fiscal pressures and eyes his 2012 reelection campaign. But Gates cautioned the peace initiative would be fraught with challenges, including locating members of the Taliban who could credibly speak for its Pakistan-based leadership. My own view is that real reconciliation talks are not likely to be able to make any substantive headway until at least this winter, he said. I think that the Taliban have to feel themselves under military pressure, and begin to believe that they cant win before theyre willing to have a serious conversation. Gates said the United States had relevant experience in Iraq, where the military eventually worked side by side with Sunni tribesmen it had earlier fought. Thats the way wars end, he said. Gates said that the human costs of the wars in Iraq and Afghanistan had made him far more wary about unleashing the might of the American armed forces. When I took this job, the US was fighting two very difficult, very costly wars, Gates said. And it has seemed to me: Lets get this business wrapped up before we go looking for more opportunities. If we were about to be attacked or had been attacked or something happened that threatened a vital US national interest, I would be the first in line to say, 'Lets go, Gates said. I will always be an advocate in terms of wars of necessity. I am just much more cautious on wars of choice. Most recently, he expressed major reservations about American intervention in Libya. He said, he has learned most clearly over the last four and a half years that wars have taken longer and been more costly in lives and treasure than anticipated.