A principal Middle East adviser to US presidential hopeful Sen. Barack Obama resigned on Friday after reports surfaced that he had been in repeated contact with members of Hamas. According to the reports, Rob Malley interviewed Hamas officials, as well as Israeli, Palestinian and other international officials, while researching reports he wrote for the International Crisis Group, a nonpartisan conflict-resolution think tank. Malley, also a former US National Security Council aide to president Bill Clinton, said that all visits with Hamas members were coordinated with the State Department, and that the government was always briefed following the meetings. Yet despite his justifications, Malley chose on Friday to resign from the campaign so as to keep critics from getting distracted. "To do my job, I have to meet with savory and unsavory people," he said, adding that after receiving yet another inquiry on the matter on Friday morning, he finally chose to step away from his advisory role. "This was a distraction for me; this was a distraction for them," he said Friday night. "It is absurd, but that is what this campaign is about." The Obama campaign downplayed the development, emphasizing that Malley's role was informal from the start. "Mr. Malley has, like hundreds of other experts, provided informal advice to the campaign," said Obama spokesman Tommy Vietor. "He has no formal role in the campaign and he will not play any role in the future."