STOCKHOLM, April 24 -- The total world military expenditure rose to 1.686 trillion U.S. dollars in 2016, an increase of 0.4 percent in real terms from 2015, according to a report released on Monday by the Stockholm International Peace Research Institute (SIPRI).

According to the report, "the United States remains the country with the highest annual military expenditure in the world. U.S. military spending grew by 1.7 percent between 2015 and 2016 to 611 billion U.S. dollars."

The think tank said the growth in U.S. military expenditure in 2016 could signal the end of a trend of decreases in spending due to the economic crisis and the withdrawal of U.S. troops from Afghanistan and Iraq. However, U.S. spending in 2016 remained 20 percent lower than its peak in 2010.

"Despite continuing legal restraints on the overall U.S. budget, increases in military spending were agreed upon by Congress," said Aude Fleurant, director of the SIPRI Arms and Military Expenditure (AMEX) program.

"Future spending patterns remain uncertain due to the changing political situation in the United States."

Meanwhile, military expenditure in Western Europe "rose for the second consecutive year and was up by 2.6 percent in 2016." There were spending increases in all but three countries in Western Europe, and Italy recorded the most notable increase, with spending rising by 11 percent between 2015 and 2016, according to the report.

Overall spending in Central Europe grew by 2.4 percent in 2016.

"The growth in spending by many countries in Central Europe can be partly attributed to the perception of Russia posing a greater threat,"said Siemon Wezeman, senior researcher at SIPRI.

"This is despite the fact that Russia's spending in 2016 was only 27 percent of the combined total of European NATO members."

Trends and patterns in military expenditure vary considerably between regions. Spending continued to grow in Asia and Oceania, Central and Eastern Europe and North Africa. By contrast, spending fell in Central America and the Caribbean, the Middle East (based on countries for which data is available), South America, and sub-Saharan Africa.

Headquartered in Stockholm, SIPRI's research covers international conflicts, armaments, arms control and disarmament.