In its 2010 yearbook, the Stockholm International Peace Research Institute, or SIPRI, said that spending between 2008 and 2009 grew 5.9 percent.

The United States remains the biggest spender, accounting for some 54 percent of the increase, the report said. China, which became the second biggest military spender in 2008, retained that position last year. France was third.

Data also showed that Asia and Oceania are increasing their military expenditures the fastest.

The global financial turmoil had little effect on governments upgrading their armed forces, even in countries whose economies were hit the hardest, SIPRI spokesman Sam Perlo-Freeman said.

"Although military spending wasn't usually a major part of the economic stimulus packages, it wasn't cut either," said Perlo-Freeman, who heads the think-tank's military expenditure project.

"For major or intermediate powers - such as the USA, China, Russia, India and Brazil - military spending represents a long-term strategic choice which they are willing to make even in hard economic times," he said.

SIPRI said that since the U.S. last year doubled its troops in Afghanistan, the country's spending there has now superseded that in Iraq.

In terms of nuclear weapon arsenals, SIPRI estimated that some 8,100 nuclear warheads are operational in the U.S., Russia, China, Britain, France, India, Pakistan and Israel. Although that is 300 fewer than a year earlier, around 2,000 of them were still "on high alert," or ready to be launched within minutes, it said.