First published by Money Metals here: https://www.moneymetals.com/news/2018/06/05/us-debt-new-record-001510

The total U.S. public debt hit a new record high of $21.145 trillion on the last day in May. As the U.S. debt increased, so did the interest expense which jumped by more than $26 billion in the first seven months of the fiscal year. That’s correct; the United States government forked out an additional $26 billion to service its debt (Oct.-Apr) versus the same period last year.