Wal-Mart Stores reported lower fourth-quarter earnings and trimmed its sales forecast for fiscal 2017 Thursday as the strong dollar and some weak international markets weighed on results.

The world's biggest retailer reported fourth-quarter earnings of $4.6 billion, down 7.9 percent from the year-ago period.

Revenues dropped 1.4 percent to $129.7 billion.

Walmart cited the drag from store closures and the strong dollar as factors in its forecast for flat sales in 2017, down from the previous outlook for 3-4 percent growth. Walmart's fiscal year started February 1.

The strong dollar hit 2016 foreign sales by $17.1 billion and is expected to reduce 2017 sales by $12 billion, Walmart executives said.

"Currency remains a headwind for our businesses as it is for many US multinational businesses," said chief financial officer Brett Biggs.

International results were also marred by political and economic instability in Brazil, slowing economic growth in China and intensifying competition in Britain, Walmart said.

Chief executive Doug McMillon said the company's China business is "on track" despite headwinds, but Brazil is "increasingly challenging" and the rise of discount grocers in Britain has left that market difficult.

International operating earnings fell 19 percent in the fourth quarter to $1.6 billion. Walmart International accounted for about 38 percent of Walmart's 2016 sales.

However, executives said they were encouraged by a 0.6 percent rise in comparable sales at US Walmart stores, the sixth consecutive quarter of growth after a lengthy slump. Walmart attributes the improvement to investment in higher employee salaries and e-commerce.

"We do see an underlying strength in our Walmart US business that wasn't there a year ago," McMillon said.

Sales in the US were dented in part by lower prices for gasoline, as well as well as deflation in meat and dairy products.

"There's not really any inflation sitting anywhere in our box," said Walmart US chief Greg Foran.

For all of 2016, Walmart reported earnings of $14.7 billion, down 9.2 percent from 2015.

Annual revenues fell 0.7 percent to $482.1 billion.

Walmart shares fell 4.7 percent in midday trade to $62.99.