WOODSTOCK, N.H., Nov 16 (Reuters) - U.S. President Joe Biden said on Tueesday he will make a final decision on his nominee to be the chair of the Federal Reserve in about four days. An official of the Biden administration said last week that the president was still weighing whether to keep Jerome Powell as chair of the Federal Reserve for a second term or elevate Fed Governor Lael Brainard to the post. (Reporting by Steve Holland, writing by Kanishka Singh; Editing by Mohammad Zargham)