WASHINGTON/GUATEMALA CITY (Reuters) – Former Guatemalan President Alejandro Giammattei has been barred from entering the U.S. over allegations of “his involvement in significant corruption,” the State Department said on Wednesday. “The State Department has credible information indicating that Giammattei accepted bribes in exchange for the performance of his public functions during his tenure as president of Guatemala, actions that undermined the rule of law and government transparency,” State Department spokesperson Matthew Miller said in a statement. The former president was criticized during…