KABUL, Afghanistan — A leaked diplomatic cable has undermined the US ambassador's relationships with key Afghan ministers at a time when ties between the two nations are already strained, a top adviser to President Hamid Karzai said Saturday.Afghan Finance Minister Omar Zakhilwal, who is well-respected by the international community, vehemently denied that he called Karzai "an extremely weak man" as reported in a Feb. 26, 2010, cable written by Ambassador Karl Eikenberry.The report is "absolutely, categorically wrong and false," Zakhilwal said at an afternoon news conference. "It certainly will not be business as usual between some ministers and the ambassador."In a raised voice, Zakhilwal accused Eikenberry of misquoting him in the cable to further Eikenberry's own opinion that Karzai was not a reliable partner. In a different cable leaked in November 2009, Eikenberry warned against sending substantial numbers of additional troops because Karzai was "not an adequate strategic partner.""The ambassador has used my name to support his views of the president," Zakhilwal said.He said the cable has not only hurt Eikenberry's relationship with him, but his ties with key ministers in the government.