Cuts to the UK's armed forces will limit the country's ability to be a major player on the world stage, former US defence secretary Robert Gates has warned.Gates said the spending squeeze would mean the UK could no longer be a full military partner of the US, according to the (BBC).Under the government's plans, by 2020 the Army will lose 20,000 personnel, the Royal Navy 6,000 and the RAF 5,000.The Ministry of Defence says Britain still has the fourth largest defence budget in the world.But Gates, who served under presidents Obama and Bush, singled out cuts to the navy as particularly damaging.Interviewed by BBC Radio 4's Today programme, he noted that - for the first time since World War One - Britain did not have an operational aircraft carrier.Gates's comments echo the concerns of other senior military figures.The UK Chief of the Defence Staff General Sir Nicholas Houghton, warned last month Britain could be left with the "spectre" of a hollowed-out force.Prime Minister David Cameron insisted in 2011 the UK retained a "pretty full spectrum capability" after the three service chiefs warned its reach would be diminished.