pauline choiu, cnn, hong kong. >>> as pauline explained, japan is the second biggest holder of u.s. the debt come with the heavy burdens of japan's post tsunami and earthquake recovery. >> reporter: the stock exchange and currency markets are holding their breath waiting for u.s. lawmakers to strike a deal. investor concern is rising as tokyo stocks are down almost across the board, reflecting that what happens on the u.s. affects japan's economy from top to bottom, second only to china in holding u.s. debt. it hoeds about 20% of american debt. if the u.s. doesn't pay its bills, it's japan partially left holding the bag. japan's economic minister says he does not believe the u.s. will default, indicating u.s. bonds still remain a good bet for japan. he says if the worst case scenario happens and if the u.s. defaults, it would unleash a similar financial crisis to what the world saw after the subprime crisis in the u.s. he urged the u.s. to clean up its debt mess. economists say the rancor in washington also tells asia, the fastest growing economic region in the world that america's