The United States have always been supporter of an independent Kosovo. Below you can find some statements on this:

http://www.whitehouse.gov/news/releases/2007/06/print/20070610-1.html

http://usinfo.state.gov/xarchives/display.html?p=washfile-english&y=2007&m=March&x=20070321142711MVyelwarC0.6473047

http://usinfo.state.gov/xarchives/display.html?p=washfile-english&y=2007&m=June&x=20070610180035uhyggep0.1505548

http://usinfo.state.gov/xarchives/display.html?p=washfile-english&y=2007&m=April&x=20070417171314MVyelwarC7.734317e-02

http://www.state.gov/p/us/rm/2007/84609.htm

http://usinfo.state.gov/xarchives/display.html?p=washfile-english&y=2007&m=April&x=20070404155517atiayduj0.3391382