A look at how US military spending compares to the rest of the world and how it has changed in the last 50 years.

US President Donald Trump is reportedly seeking to increase the country's 2018 defence budget by $54bn.

The proposal, which could entail big cuts in foreign aid and spending on domestic agencies, follows campaign promises by the Republican candidate to boost military spending.

"This budget follows through on my promise on keeping Americans safe ... It will include a historic increase in budget spending," Trump said on Monday.

The US spends by far the most money of any country on its military, around $600bn annually, or about one third of global defence spending.

China, the world's second biggest military spender, trails the US by more than $350bn.