BERLIN (Reuters) - Germany wants to reach out to the future U.S. administration under President-elect Donald Trump to safeguard essential trans-Atlantic relations, Chancellor Angela Merkel’s foreign policy advisor Christoph Heusgen said on Wednesday. Speaking to lawmakers in Merkel’s conservative party, Heusgen also said Germany would have to shoulder more international responsibilities in future.  He said Germany would steadily increase military spending towards the NATO goal of 2 percent of gross domestic product.   Earlier, Merkel said there would be contacts at all levels with the United States in the run up to meetings of the Group of 20 this year of which Germany is the chair. 