WASHINGTON, Aug 20 (Reuters) - President Joe Biden plans to nominate Rahm Emanuel, a former U.S. lawmaker who served as chief of staff to then-President Barack Obama and as mayor of Chicago, to be ambassador to Japan, the White House said in a statement on Friday. White House officials lauded Emanuel"s experience and long years of public service in announcing the nomination. Emanuel, 61, headed the finance committee for Bill Clinton"s presidential campaign in 1992 and later served as a senior adviser to Clinton on policy and strategy. He was Obama"s chief of staff for over a year before resigning to run for election as mayor of Chicago, the third largest U.S. city. The White House highlighted Emanuel"s work on revitalizing Chicago, which hosted the 2012 NATO summit and lead the country in attracting foreign direct investment for six consecutive years. He is currently national chair of the Advisory Council of Youth Guidance’s Becoming a Man (BAM) mentoring program. Emanuel said he was honored to be tapped for the job. "The alliance between the United States and Japan is the cornerstone of peace and prosperity in a free and open Indo-Pacific," he said in a statement. The longtime Democratic politician joins a long list of ambassadors nominated by Biden who are awaiting confirmation hearings and confirmation by the U.S. Senate. The White House has grown increasingly frustrated about the slow pace of confirmations for nearly 300 of Biden"s nominees, with many nominations being held up by Senator Ted Cruz and other Republican senators to register frustration over various issues. Reporting by Eric Beech, David Brunnstrom and Andrea Shalal; editing by Jonathan Oatis Our Standards: The Thomson Reuters Trust Principles.