US Director of National Intelligence James Clapper has submitted his letter of resignation, he has told a congressional panel, BBC reports. He told the House Intelligence Committee that "it felt pretty good". The 75-year-old top American spy had been expected to step aside, as President-elect Donald Trump prepares to appoint his own officials. Analysts believe that he is sending a signal to the Trump administration that they must now speed up the transition. Clapper will remain in post until President Barack Obama leaves office. "I submitted my letter of resignation last night which felt pretty good. I've got 64 days left," he said.