WASHINGTON (Online) - The US officials are concerned over possible retaliatory steps that Pakistan may take, US media reported on Monday. According to the Wall Street Journal report, US officials are concerned over steps that Pakistan might take in retaliation to NATO strike. 'They are pondering over the possible repercussion of NATOs act of aggression. They believe the cut in NATO supplies is a very critical issue and in days to come it could further complicate the situation. 'It is being speculated that the US mulls over alternate routes to continue defence supplies from Central Asia, it said. The real issue could prop up when Pakistan disallows the use of its air space to US, it added. The US also mulls over stopping Pakistan aid to pressure it for withdrawing retaliatory steps, the paper said. The daily said that sharp spike in tensions threw fresh doubt on US efforts to coax greater cooperation from Pakistan in rooting out militants on its side of the Afghan border and bringing the Taliban to the negotiating table to try to wind down the 10-year-old war. Current and former US officials said the timing of the crisis couldnt be worse for the Obama administration, which plans to accelerate the drawdown of US forces from Afghanistan next year and then possibly shift to a more limited train, advice and assist mission, it said. A sustained breakdown in cooperation with Pakistan could make it more difficult for the US to make and sustain security gains, particularly in eastern provinces, and thereby make it harder to pull out, WSJ said. The New York Times Monday said Pakistan had reason to feel that the US had violated its sovereignty. The leading US newspaper has also cited a US democratic Senator Richard J. Durbin who said while talking to FOX news, 'Imagine how we would feel if it had been 24 American soldiers killed by Pakistani forces at this moment. The paper further said the reaction inside Pakistan nonetheless followed a now-familiar pattern of anger and tit-for-tat retaliation. So did the American response of regret with frustration and suspicion, he said. 'Each sides actions reflected a deepening distrust that gets harder to repair with each clash. The paper also citing Vali Nasr, a former deputy to the administrations regional envoy, Richard C. Holbrooke, and now a professor at Tufts University that the United States effectively has not one but two strategies for winning the war in Afghanistan. In recent months American forces have complained that they have taken mortar and rocket fire from positions in Pak territory, as officials said they did early Saturday in the Mohmand region, just north of the Khyber Pass, prompting American troops to call in air strikes.