The number of NATO nations meeting or exceeding the alliance's target of spending 2% of their gross domestic product (GDP) on defence has increased, according to the latest official estimates.
The UK, one of 11 nations believed to be hitting the target, is fourth in the list of proportional spending, while the Slovak Republic has joined those who are on track.
A real change estimate increase of 2.69% spending within the military alliance has seen members contributing more.
NATO data estimates there has been a UK defence spending boost in 2019 from 2.1% to 2.32%.
The US remains the alliance's biggest contributor, spending 3.73% of its GDP, while Greece has moved into second place at 2.68%.
Despite Bulgaria's spend shooting from 1.45% in 2018 to a 3.15% following a $1.3bn F-16 fighter jet deal in 2019, the data shows it is now failing to hit the target – falling from second to 16th place with an estimated 1.6% in 2020.
Latvia (2.27%), Lithuania (2.13%), Poland (2.31%) and Romania (2.07%) are all legally bound to meet the 2% target, so all make the top 10.
Canada sits at 21st on the list, spending 1.42% of its GDP on defence – a rise from 1.29% in 2019.
Presenting his annual report, Jens Stoltenberg said: "Despite the economic effect of COVID-19, 2020 was the sixth consecutive year of increase in defence spending across EU allies and Canada, with an increase in real terms in 2020 of 3.9%."
The increase in 2019 was 3.6% in real terms.
WATCH: NATO Secretary General Jens Stoltenberg announces a 3.9% increase in defence spending across EU allies and Canada.
France is estimated to have spent 2.04% of GDP on defence in 2020, while Germany is reportedly hitting 1.56% – an increase on 2019, but still below the NATO guideline.
Luxembourg was at the bottom of the list with a GDP spend of 0.57%, now the only nation estimated below 1%, while Belgium (1.07%) and Slovenia (1.1%) also lie in the bottom three.
NATO is made up of 30 countries, an increase of one after the Republic of North Macedonia (1.27%) joined in 2020.
Iceland, which does not have any armed forces, was not featured on the list.
Formed in the aftermath of the Second World War, NATO's original goals were to secure peace in Europe, promote cooperation among its members and to counter the threat posed by the USSR, also known as the Soviet Union.
Cover image: Tanks taking part in training in Estonia as part of NATO's enhanced Forward Presence Battlegroup last month (Picture: NATO).