North Korea's military has come under the spotlight after the United States joined South Korea and Ukraine this week to accuse Pyongyang of dispatching thousands of troops to Russia, potentially to ready them for combat in the Ukraine war.

Here are some facts and estimates on what is known about the Korean People’s Army (KPA) and other elements of the North's military:

How many troops does North Korea have?

The KPA, with an estimated 1.3 million active personnel, is one of the world's largest militaries, behind only far bigger countries such as China and the United States.

According to data from the International Institute for Strategic Studies (IISS), a think-tank, North Korea also has about 600,000 reservists and 5.7 million Worker/Peasant Red Guard reservists, among many unarmed units.

The KPA is divided into the army, air force, navy and strategic forces, which are armed with ballistic missiles that can be equipped with nuclear warheads.

North Korea is one of the most militarised societies in the world and all men between the ages of 17 and 30 must enlist for military service lasting between 3 and 12 years.

The air force is estimated to have about 110,000 personnel and the navy 60,000.

Does North Korea have a strong military?

North Korea is one of nine countries in the world known to have nuclear weapons.

It has built a number of missiles that it says can be tipped with nuclear bombs, ranging from short-range tactical weapons to huge intercontinental ballistic missiles (ICBMs) with the potential range to reach anywhere in the United States.

The KPA has a huge amount of conventional military equipment, though much is ageing and outdated. This includes Soviet-era tanks such as the T-34, Chinese models as well as domestically produced tanks like the Chonma-ho or Songun-ho.

The KPA's armoured and mechanised units have more than 6,900 tanks and armoured vehicles, according to the South Korean military's 2022 Defense White Paper.

The air force has an inventory of more than 400 fighter aircraft, 80 light bombers and more than 200 transport aircraft, according to the IISS.

But many of its aircraft date back to the Soviet era, with some thought to be 40 to 80 years old and not serviceable or part of the active fleet.

The Korean People's Army Naval Force (KPANF) has about 470 surface vessels, including guided missile ships, torpedo boats, small patrol vessels, and fire support boats, according to the South Korea's 2022 Defense White Paper.

It has about 70 submarines, including Romeo-class vessels of Soviet-era design, and midget submarines. In the last few years, North Korea has moved to boost its navy with new nuclear weapons, including an underwater drone, warships, and its first operational missile submarine.

How does North Korea use its military?

Most of the North's army is deployed near the 248-km (154-mile) long Demilitarized Zone (DMZ) border dividing it from South Korea.

The KPA has sought to make up for perceived shortfalls by emphasising so-called asymmetric capabilities, including special operations forces, weapons of mass destruction like chemical and biological weapons and artillery targeting Seoul. Pyongyang's ballistic missile nuclear development has also played a bigger role in its strategic thinking. North Korea says its arsenal of nuclear weapons and ballistic missiles to carry them are necessary to counter threats from the United States and its allies, which fought the North during the 1950-1953 Korean War.

The military has 6,800 cyber warfare personnel developing new technologies to reinforce North Korean cyber forces, according to South Korea's white paper.

How much money does North Korea spend on defence?

Between 2010 and 2020, military expenditure accounted for an estimated 20%-30% of North Korea's GDP annually, according to the The World Factbook - CIA.

In January, North Korea said it would spend nearly 16% of state expenditure on defence.