WASHINGTON - President Barack Obama has asked the Pentagon to plan for a complete withdrawal of US forces from Afghanistan by the end of the year amid a dispute over a security pact, but continues to leave open the possibility that some troops could remain after 2014 - options he discussed Tuesday with Afghan President Hamid Karzai. Diplomats noted that the move raised the stakes in the collapsing relationship between the Obama administration and the Karzai government in Afghanistan — as relations hit a new low.In a phone call between the two heads of state, Hamid Karzai told Barack Obama that he would not sign a new agreement to keep American forces in the country, leaving it to the next president instead. In response, Obama told Karzai that the US would entirely withdraw before the end of the year, and ordered the Pentagon to produce a full-retreat option.The White House detailed the "contingency planning" in a statement following the phone call between Obama and Karzai.Obama and Karzai have rarely spoken in recent months, a reflection of the White House's frustration with the Afghan leader.Obama told Karzai during a Tuesday morning phone call that while he would prefer Karzai or his successor to sign the so-called Bilateral Security Agreement reached with the Afghans in November, “the United States is moving forward with additional contingency planning,” according to a White House description of the call.Since November, the Pentagon has urged Karzai to sign the deal, but has stopped short of formally preparing for what is known as the “zero option,” or full withdrawal.But Defence Secretary Chuck Hagel said Tuesday that it was prudent “to ensure adequate plans are in place to accomplish an orderly withdrawal by the end of the year should the United States not keep any troops in Afghanistan after 2014”.Hagel said that over the next several months, the US military will prepare “various options” for US and Nato leaders, including a full withdrawal of the approximately 37,000 US troops in Afghanistan, as well as the post-2014 missions of counter-terrorism and training for the Afghan security forces it has long desired.Relations between the Afghan government and the US military have been acutely strained over the past several weeks. Earlier this month, the Kabul-based military command, under General Joseph Dunford, sharply rebuked its erstwhile Afghanistan partners for releasing 65 detainees it said had US and Afghan blood on their hands.Dunford is said to favour a residual force in Afghanistan of around 10,000 troops, fearing that a full US departure after December will leave Afghanistan vulnerable to a reinvigorated push from the Taliban insurgents the US and its allies have failed to subdue after 12 years of war. Administration officials said that they expected to discuss a future presence or full withdrawal from Afghanistan in Brussels at a Nato summit of defense ministers later this week. Preparations for a withdrawal from Afghanistan are complicated by the fact that the use of air bases there are not solely focused on waging war. Bases like Kandahar in the south and Jalalabad in the east are also platforms for flying surveillance and armed drones into neighboring Pakistan, and surveillance drones have also likely flown from Kandahar into Iran. Losing access to Afghan air bases may likely prompt the US to look for alternative regional launchpads in central Asian states, an uncertain prospect complicated by their dismal human rights records. In 2005, Uzbekistan revoked US access to its Karshi-Khanabad air base following a diplomatic row over a bloody crackdown in Andijan province.On Tuesday afternoon, Hagel was scheduled to meet at the White House with secretary of state John Kerry and Susan Rice, Obama’s national security adviser. Should an elected successor to Karzai also decline to sign the bilateral accord, it would mark the second time in three years that the host government of a bloody, protracted US military campaign rebuked its Washington sponsor. In 2011, the Iraqi government refused to allow Obama to maintain a residual presence in Iraq – a decision Obama used to campaign for reelection on a tide of ending US wars, and which has come under harsh scrutiny after forces loyal to al-Qaeda proclaimed themselves in control of parts of Anbar province last month.This news was published in The Nation newspaper. Read complete newspaper of 26-Feb-2014 here.