WASHINGTON (AP) - The top U.S. military commander in the Middle East is saying he envisioned a post-2014 force in Afghanistan of about 20,000 troops, far more than the number the Obama administration and NATO are considering. Gen. James Mattis, head of U.S. Central Command, is telling the Senate Armed Services Committee that he personally recommended the U.S. leave 13,600 troops in Afghanistan and that he assumed the NATO allies would probably contribute "around 50 percent" of the U.S. total, which would be roughly 6,500. U.S. and NATO leaders revealed late last month that they may keep between 8,000 and 12,000 troops in Afghanistan after combat troops leave at the end of next year. Mattis says the U.S. and NATO must send a message of commitment to Afghanistan and the region.