German tennis player Angelique Kerber said on Tuesday in Munich, after winning the US Open, that she wants to remain on top of the Women's Tennis Association (WTA) rankings as long as possible.Kerber, the first German to top the WTA ranking after legend Steffi Graf, emphasised that she will do what it takes to achieve this goal, reports Efe.The German, who will take a few days off and return to competitions before the end of the month, added that she is happy she will get some time to put down her racquet, get some sleep and see her friends and family.