The national debt surpassed a record US$40 trillion on Wednesday, a staggering milestone as defence costs, social programmes like Social Security and Medicare, and interest on the burgeoning deficit make up an enormous share of federal spending. The milestone figure was recorded just five months after the United States hit a record US$39-trillion debt in March. It reached US$38 trillion five months before that, in October.

The national debt is now over $40 trillion, a historic high that economists warn is bad news for the United States.

Budget watchdog groups have been anticipating the news for weeks, with some issuing stark warnings of a debt crisis