The Stockholm International Peace Research Institute (SIPRI) said in a statement the United States, China and Russia were the top spenders in 2023, Reuters reported.
Nan Tian, senior researcher at SIPRI's Military Expenditure and Arms Production Program, said: "States are prioritizing military strength but they risk an action–reaction spiral in the increasingly volatile geopolitical and security landscape."
SIPRI said Russia raised spending by 24% to an estimated $109 billion. Ukraine increased spending by 51% to $65 billion and received at least $35 billion in military aid from other countries.
"Combined, this aid and Ukraine’s own military spending were equivalent to about 91% of Russian spending," the think-tank said.
It said NATO member countries' spending totaled 55% of the world’s expenditure.
"For European NATO states, the past two years of war in Ukraine have fundamentally changed the security outlook," SIPRI researcher Lorenzo Scarazzato said.
"This shift in threat perceptions is reflected in growing shares of GDP being directed towards military spending, with the NATO target of 2% increasingly being seen as a baseline rather than a threshold to reach."
NATO member states are expected to set aside at least 2% of gross domestic product for defense expenditure by the alliance.
SIPRI said most European NATO members had boosted such spending. The US raised it by 2% to $916 billion, representing around two-thirds of total NATO military spending.
The percentage changes are expressed in real terms, in constant 2022 prices, SIPRI added.