WASHINGTON | Wed Dec 8, 2010 4:03pm EST WASHINGTON (Reuters) - New Mexico Governor Bill Richardson said on Wednesday he would travel to North Korea from December 16-20, hoping to ease mounting tensions with Pyongyang over its nuclear program and belligerence toward South Korea. "I am increasingly concerned with the recent actions by the North Koreans, which have raised tensions and are contributing to instability on the Korean Peninsula," Richardson said in a statement, saying he was going as a private citizen. "I am not carrying any messages, but I want to be helpful during this volatile period," Richardson said....