KABUL (Agencies) Disagreements between Washington and Kabul are natural and should be taken in stride, the US ambassador to Afghanistan said Saturday, as the sides sought to move past friction that surfaced after Afghan President Hamid Karzais harsh criticism of the West. Karzai has lashed out at the United Nations and the international community over alleged interference in last years fraud-tarnished presidential election, at one point even threatening to join the insurgency if the West didnt back off. Such occasional flare-ups are inevitable, Karl Eikenberry told reporters at the end of a news conference in Kabul. This is not easy work to do, he said. We can have different perspectives. Karzais comments had been called disturbing by the White House and officials had suggested they could cancel Karzais planned visit to Washington in May if they continued. Afghan President Karzai took small but public steps on Saturday to signal he was still friends with the US after a war of words that tested their alliance. In what appeared to be a choreographed effort to portray the relationship in the best light, Karzai visited the headquarters of General Stanley McChrystal, the US and Nato commander, down the road from Karzais own palace in central Kabul. Karzai warmly greeted McChrystal and his aides, and attended a briefing of top brass of McChrystals International Security Assistance Force (Isaf). Reporters were then invited to film the two men having lunch with a group of Nato officers. Karzai had sparked the row by accusing Western countries and officials of perpetrating election fraud in Afghanistan, in comments the White House called disturbing and untrue, and the State Department called preposterous. In other remarks in the last ten days, Karzai said there was a fine line between cooperation and occupation, and that Afghans had to see that their government were not puppets. McChrystals spokesman, Lt-Col Tadd Sholtis, said Karzais visit to the Isaf headquarters - the first time he has attended an operational briefing there was a sign of the his increased leadership role in the conduct of the war. Were obviously working on the partnership here, he said. I think its just part of a larger engagement on his part with the strategic and operational direction of what were doing. Sholtis said Karzais invitation to Isaf headquarters had been long-standing, and he could not comment on whether Karzais decision to attend was motivated by a desire to show friendship after the strain the alliance had taken in the past two weeks.