WASHINGTON (AP) — A new government analysis of the House GOP tax bill says its true costs to the nation's debt are at least $259 billion greater over the coming decade.

That's because of the interest costs the government has to absorb to borrow more money to keep the government running. That puts the debt cost of the measure at $1.7 trillion over 10 years.

The Congressional Budget Office study actually understates the measure's true cost since it's based on last week's version of the bill. An amendment added by Ways and Means Committee Republicans on Monday added $161 billion to the cost of the bill, mostly by watering down an international tax provision.