President Bush has praised the work of Lewis Libby, but said he has accepted the resignation of the indicted White House aide. Mr. Bush on Friday said Mr. Libby worked tirelessly on behalf of the American people and served the administration through extraordinary times. He said the investigation and ongoing legal proceedings are "serious." Mr. Bush said suspects are presumed innocent and entitled to due process and a fair trial in the American judicial system. He expressed sadness about today's news but said he needs to focus on the issues facing the country. Mr. Bush made the comments at the White House before heading to the Camp David presidential retreat outside Washington.