Global military spending last year reached a staggering $US2.2 trillion ($3.4 trillion), a rise of 9 per cent, according to UK-based International Institute for Strategic Studies (IISS).
While its research found wars in Ukraine and the Middle East were major drivers of the increase, tensions in Indo-China were also causing nations, including Australia, to ramp up their defence budgets.
Superpower rivalry between the United States and China had pushed nations in the region into the camps of Washington or Beijing, the IISS said. There has also been increased military co-operation, including drills held by Australian and Philippines soldiers showed here.
The largest increase by a US ally in the Indo Pacific was by the island Taiwan, long regarded as a renegade territory by China.
The self-governing island increased its military budget by about 20 per cent last year amid concerns about a Chinese attack.
Taiwan has bought large stocks of US-made weaponry, such as these ship-launched missiles.
China is also forging military co-operation with countries that reject the Western-led concept of an international rules-based order.
They include North Korea, led by Kim Jong-un, who has pledged to raise military spending in fiery rhetoric aimed at the US and its allies in the regio.
Click ahead to find the 15 nations with the biggest defence budgets.
Canada is a key member of NATO, participating in many operational exercises and serving in many small and major conflicts.
The country announced it would spend billions of dollars replacing existing Hornet jet fighters with American-made F-35 warplanes.
Canada and the US make up the strategically vital North American Aerospace Defence Command (NORAD).
Last year the Brazilian government unveiled plans for a major increase in spending on its army, navy and air force as it bids to become a major regional power.
Brazil aims to strengthen its borders, protect the Amazon region and safeguard offshore oil finds.
Ukraine's military spending has leapt since it was invaded by Russia in February 2022.
The country has acquired massive shipments of Western-made heavy weapons including tanks, howitzers and missiles, but further key shipments from the United States remain in doubt due to political wrangling by American politicians.
Italy, like many European countries, announced an increase in defence spending after Russia's invasion of Ukraine in 2022.
The Italian Armed Forces are made up by the Italian Army, the Italian Navy and the Italian Air Force.
A fourth branch of the armed forces, known as the Carabinieri, take on the role as the nation's military police and are also involved in missions and operations abroad as a combat force.
Australia's armed forces will undergo a major expansion, with the nation's navy acquiring nuclear-powered submarines under the AUKUS defence pact.
A landmark defence review last year highlighted the growing tensions in the Indo Pacific and how the Australian Defence Force must respond.
The Australian government is committed to a major defence overhaul, with long range strike weapons a priority.
South Korea is a close ally of the US and continuously invests in modernising its defence forces
Tensions between the two Koreas bolsters military spending.
A peace treaty between North and South Korea set up a four-kilometre wide demilitarised zone across the peninsula.
Japan, a close ally of Australia and the US, is increasingly concerned about growing Chinese assertiveness in the Indo-Pacific as well as the nuclear ambitions of North Korea.
Among the biggest planned purchases by Japan are six F-35B stealth fighter jets, costing $US183 million each, for deployment this year.
French military spending has ramped up under the government of President Emmanuel Macron.
In 2023, he announced yearly rises in defence budgets into the 2030s to meet mulitple threats.
Spending has been targeted towards arming drones and hiring "cyberfighters", as well as increasing domestic military deployment after a string of deadly extremist attacks.
After the 2022 Russian invasion of Ukraine, the German government announced a massive increase in defence spending.
The German government has been under pressure from its NATO allies to push up its military budget.
Saudi Arabia's defence spending has swelled to one of the largest in the world as a result of growing threats from terrorist organisations and struggles for regional dominance against Iran.
The Middle East kingdom recently acquired the American-built F-15SA fighter jet and Spanish corvettes for its navy.
Britain has a long and proud military history and last year its government pledged to increase defence funding by $US6 billion over the next two years in response to Russia's invasion of Ukraine and the challenge posed by China.
The extra money will be used, in part, to replenish Britain's ammunition stocks, depleted from supplying Ukraine in its defence against Russia.
Some will also go towards the AUKUS deal to build nuclear-powered submarines for Australia.
India spends big on defence and has consistently ranked among the leading defence importers worldwide for a number of years.
The Indian government announced further increases in military spending in coming years amid tensions with China.
It wants to upgrade its squadrons of fighter jets and build new roads along the contested border with China.
Russia has pivoted its economy to a full war footing since it invaded Ukraine.
"Russia has raised its official defence budget for 2024 more than 60 per cent year-on-year. Total military spending now represents one third of its national budget and will reach about 7.5 per cent of GDP, signalling the focus on its war effort," the IISS report said.
But the Russian military is losing fighting men and equipment at a staggering rate. It has lost more than 3000 armoured fighting vehicles in the past year alone, the report said
China remained in second spot after its 29th-consecutive annual rise in military spending.
China says its military is strictly for defensive purposes but takes a broad view of what constitutes threats to its core interests — including protecting maritime territory that is in dispute with neighbouring countries such as the South China Sea.
The People's Liberation Army is the world's largest military force with about 2 million active personnel.
The United States remains the world's biggest military spender, accounting for 41 per cent of all expenditure and 70 per cent of spending in the NATO military alliance.
American military planners are increasingly concerned about China's rapid military build-up, particularly in the area of advanced hypersonic weapons.
The US is planning new spending across all four services of its armed forces: navy, army, air force and marine corps.