While U.S. military spending from 2007 to 2014 remained largely flat, military spending among other nations among the world's top 15 military spenders has skyrocketed, according to data released Monday by the Stockholm International Peace Research Institute.

The U.S. spent about $610 billion on its military in 2014, making up nearly 43 percent of the funds spent by the top 15 spending nations. Trailing in a distant second was China, which spent an estimated $216 billion (15.1 percent), followed by Russia, which spent an estimated $84.5 billion (5.9 percent) and Saudi Arabia, which spent $80.8 billion (5.7 percent), according to the data.

Altogether, military spending by the top 15 countries in 2014 came to about $1.4 trillion, representing about 80 percent of worldwide military spending.

But U.S. military spending fell slightly between 2005 and 2014, by 0.4 percent, a product of tight fiscal constraints. Spending by some Western European countries and Japan also fell.

Meanwhile, spending by China, which has increasingly sought to assert its dominance in Asia, surged 167 percent. The estimated $216 billion it spent in 2014 accounted for just under one half of all military spending by Asian and Pacific countries, according to SIPRI.

Military spending by the UAE and Saudi Arabia skyrocketed by 135 percent and 112 percent, respectively, a reflection in part of the worsening security situation, said SIPRI's SIRPI's Sam Perlo-Freeman in a statement. The two countries also represented 9 percent of all arms exports from 2010 to 2014, SIPRI reported in March.

With its backing of rebels in eastern Ukraine and other initiatives to bolster its international standing, Russia's spending rose by 97 percent. But like some Middle Eastern countries, Russia's military budget has been hit by a fall in oil prices, with a 5 percent cut planned from what was originally slated for 2015. SIPRI notes, however, that even with that cut, Russia's 2015 military budget represents "a significant increase on spending in 2014" compared with past years.