All five legally recognised nuclear states as defined by the non-proliferation treaty – China, France, Russia, the UK and US – are either deploying new nuclear weapons and delivery systems or plan to do so, according to a leading international research organisation.

The countries "appear determined to retain their nuclear arsenals indefinitely", says the latest yearbook published by the Stockholm International Peace Research Institute (Sipri).

At the start of 2013, eight states – the US, Russia, UK, France, China, India, Pakistan and Israel – possessed approximately 4,400 operational nuclear weapons. Nearly 2,000 of these are kept in a state of high operational alert. If all nuclear warheads are counted, these states together possess a total of approximately 17,265 nuclear weapons, says the Sipri report.

Signatories of the non-proliferation treaty, including the UK, pledge to work towards nuclear disarmament.

"Once again there was little to inspire hope that the nuclear-weapon-possessing states are genuinely willing to give up their nuclear arsenals. The long-term modernisation programmes under way in these states suggest that nuclear weapons are still a marker of international status and power," said the Sipri senior researcher Shannon Kile.

Of the five "official" nuclear states, China appears to be expanding its nuclear arsenal while India and Pakistan are expanding both their nuclear weapon stockpiles and their missile delivery capabilities, Sipri says. Pakistan is also expanding its main plutonium-production complex at Khushab, Punjab.

Sipri estimates that Israel has approximately 80 intact nuclear weapons, 50 for its Jericho II medium-range ballistic missiles and 30 for gravity bombs carried by aircraft. Israel may also have produced non-strategic nuclear weapons, including artillery shells and atomic demolition munitions, says the yearbook.

It estimates world military expenditure in 2012 to have been $1.756tn (£1.157tn), representing 2.5% of global gross domestic product (GDP) – or $249 for each person in the world. Though a little lower than the previous two years, the total is higher than in any year between the end of the second world war and 2010.

The distribution of global spending in 2012 shows a shift from the west to other parts of the world, including the Middle East and north Africa, eastern Europe and the developing world.

The international arms trade in major conventional weapons grew by 17% between 2003 and 2012. The five largest suppliers over the past five years – the US, Russia, Germany, France and China – accounted for 75% of all conventional arms exports.

China may represent "the vanguard of an increase in the significance of Asian suppliers in the international arms trade, as South Korea is an emerging arms supplier and Japan and Singapore have potential to become major suppliers", says Sipri.