The Navy secretary has spent more than a full year of his five-year tenure on overseas travel, racking up more than 930,000 miles on trips that cost taxpayers more than $4.7 million.

America’s top military leader arrived in Iraq on Saturday on a previously unannounced visit, his first since a U.S.-led coalition began launching airstrikes against the extremist Islamic State group.

The Pentagon warned Congress on Thursday that the long, drawn-out military campaign against Islamic State militants is just beginning and could expand to include modest numbers of U.S. forces fighting alongside Iraqi troops.