Oslo - Senator Patrick Leahy urged Washington yesterday to be more flexible in negotiations on a global treaty banning anti-personnel landmines or risk being excluded from an accord. The Vermont Democrat said the US had found virtually no support for the string of exceptions and caveats it was demanding at talks underway in Oslo. He urged Washington policymakers, who are wary of a pact which powers like Russia and China show no sign of joining, to "go back to the drawing board - right now". Mr Leahy was speaking as 120 countries began the second week of a 19day conference to hammer out the text of a convention. "It cries out for the moral leadership of the US."