By John Geddie and Valerie Volcovici WASHINGTON D.C. (Reuters) – The United States is seeking to form a coalition of countries to drive negotiations on a global plastic pollution treaty, weeks after a similar group involving several other G7 nations was launched, according to a document seen by Reuters. The move underlines its desire to keep the treaty’s focus on the efforts of individual countries in a model similar to the 2015 Paris climate accord, rather than provide new universal rules favoured by other major nations, according to six government and civil society sources involved in the ta…