NEW : About half of U.S. cargo comes into Afghanistan via Pakistan , Pentagon says . Comment: Spokesman : `` We do n't think it 's a very serious problem '' Pakistan says 3 of its soldiers were killed during NATO attack on insurgents .
NEW : About half of U.S. cargo comes into Afghanistan via Pakistan , Pentagon says . ISAF spokesman says Torkham Gate in the Khyber Agency is closed . Spokesman : `` We do n't think it 's a very serious problem '' Pakistan says 3 of its soldiers were killed during NATO attack on insurgents .