At 09 : 00 Walker requested the US Air Force to make a maximum effort along the Naktong River from Toksong @-@ dong , just above the US 2nd Division boundary , southward and to a depth of 15 miles ( 24 km ) west of the river . He wanted the Air Force to isolate the battlefield and prevent further North Korean reinforcements and supplies from moving across the river in support of the North Korean spearhead units . The Far East Command requested the US Navy to join in the air effort , and the US Seventh Fleet turned back from its strikes in the Inch 'on @-@ Seoul area and sped southward at full steam toward the southern battle front . Walker came to the US 2nd Division front at 12 : 00 and ordered the division to hold at all costs . He had already ordered ground reinforcements to the Yongsan area .