U.S. job cuts soared to a nearly four-year high in July as the military announced plans to reduce troop and civilian workforce payrolls, according to outplacement consultancy Challenger, Gray & Christmas.

Employers based in the United States announced 105,696 layoffs last month, the first time monthly reductions exceeded 100,000 since September 2011. A year ago, U.S. companies announced plans to cut 46,887 jobs.

The Challenger report comes a day before the Labor Department's crucial July jobs report. A weak report would make it less likely for the Federal Reserve to announce its first interest rate increase in nine years at its September meeting.



Read MoreUS private sector jobs fall short in July



July's reductions bring the year-to-date total to 393,368 cuts, a 34 percent increase from the period last year.