WASHINGTON (Reuters) - The White House said on Wednesday a drop in GDP in the fourth quarter is driven in large part by a decrease in defense spending and accused Republicans of "political brinkmanship" for threatening to let more defense cuts take effect.

White House spokesman Jay Carney said a looming March 1 deadline when defense cuts take effect absent a broader budget deal stands to hurt the U.S. economy and taxpayers unless addressed.

He said Republican threats to let the cuts take place amount to "political brinkmanship" that harms only Americans.

(Reporting By Steve Holland; Editing by Sandra Maler)