The total military expenditure of NATO members has been recorded as $1,155bn.
This is an increase of $59bn since 2020 when adjusted for inflation, of which the USA accounted for nearly $23bn.
These details come from the latest international defence expenditure analysis released by the Ministry of Defence (MOD).
According to the latest details, seven NATO countries are meeting the guideline to spend 2% of GDP on defence.
These countries are Greece, the USA, the UK, Poland, Latvia, Estonia and Croatia.
The UK remains the second largest spender in NATO, after the US.
In 2021, 2.3% was the UK expenditure on defence as a percentage of national GDP.
Defence Secretary Ben Wallace has regularly called for an increase in defence spending, with former Prime Minister Liz Truss pledging to increase defence spending to 3% by 2030.
The UK's newly appointed Prime Minister Rishi Sunak has yet to make any pledges.
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The UK, however, already meets NATO's 2% target – since its introduction in 2006, the UK has made the target every year.
According to the International Institute for Strategic Studies (IISS) think tank, the UK ranks third in the global defence expenditure rankings – it has moved up from fourth position since 2020.
The UK's total worldwide military expenditure in 2021 was $2,113bn, as estimated by the Stockholm International Peace Research Institute (SIPRI), the independent resource on global security.
The USA was the world's largest spender, accounting for 38% of the total global spending.