Global military spending increased by 2.6 percent to $1,981 billion (about 1,650 billion euros) in 2020, when global GDP shrank 4.4 percent, according to a report from the Stockholm International Peace Research Institute (SIPRI).

Diego Lopes da Silva, one of report's authors, told AFP the development was unexpected.

"Because of the pandemic, one would think military spending would decrease," he said.

"But it's possible to conclude with some certainty that Covid-19 did not have a significant impact on global military spending, in 2020 at least," Lopes da Silva said.

He cautioned however that due to the nature of military spending, it could take time for countries "to adapt to the shock".

The fact that military spending continued to increase in a year with an economic downturn meant the "military burden", or the share of military spending out of total GDP, had increased as well.

The overall share rose from 2.2 percent to 2.4 percent, the largest year-on-year increase since the financial crisis of 2009.

As a result, more NATO members hit the Alliance's guideline target of spending at least two percent of GDP on their military, with 12 countries doing so in 2020 compared to nine in 2019.

- Some Covid effects -

There were however indications the pandemic had affected some countries.

Nations such as Chile and South Korea openly decided to reappropriate military funds in response to the pandemic.

"Other countries, such as Brazil and Russia, did not explicitly say this was reallocated because of the pandemic, but they have spent considerably less than their original budget for 2020," Lopes da Silva said.

Another response, as in Hungary for example, was to increase military spending "as part of a stimulus package in response to the pandemic".

Lopes da Silva noted many countries responded to the 2008-2009 economic crisis by adopting austerity measures, but "this time around it might not be the case".

The world's two biggest spenders by far were the US and China, with Washington accounting for 39 percent of overall expenditure and Beijing for 13 percent.

China's military spending has risen in tandem with its growing economy and has seen an increase for 26 consecutive years, reaching an estimated $252 billion in 2020.

The US also increased its spending for the third year in a row in 2020, after seven years of reductions.

"This reflects growing concerns over perceived threats from strategic competitors such as China and Russia, as well as the Trump administration's drive to bolster what it saw as a depleted US military," Alexandra Marksteiner, another author of the report, said in a statement.

Lopes da Silva however noted that the new "Biden administration has not given any indications that it will reduce military spending."