North Korea is believed to have more than 800 ballistic missiles, including long-range missiles which could one day strike the US. The BBC looks at Pyongyang's missile programme, which has mainly been developed from the Scud missile.
North Korea first obtained tactical missiles from the Soviet Union as early as 1969, but its first Scuds reportedly came via Egypt in 1976.
Egypt is believed to have supplied North Korea with Scud-B missiles and designs in return for its support against Israel in the Yom Kippur War.
POTENTIAL RANGE OF NORTH KOREAN MISSILES
The map shows estimated maximum range of a successful launch. Range is also affected by the size of the payload.
By 1984, North Korea was building its own Scud-Bs and developed new missiles, the Scud-C and a medium-range missile, the Nodong. Its latest missile combines these technologies to give a long-range missile, the Taepodong.
In July 2006, it test-fired a new missile called the Taepodong-2, which experts say could have a range of up to 10,000km (6,200 miles). The missile failed shortly after launch.
The test took place from the Musudan-ri complex on the East coast of the Korean peninsula. Analysis of satellite images of the area appears to show a range of missile fabrication, fuelling, testing and control facilities.
North Korea has a variety of short-range missiles. The KN-02 is thought to be the most accurate, but its range - around 100-120km - is the shortest.
The KN-02 missile could be aimed at key targets in South Korea such as military installations south of the border.
The Scud-B and C have ranges of 300km and 500km respectively. It is thought that these missiles could deliver conventional warheads.
The Scud-B and C have both been tested and deployed. These missiles would enable North Korea to strike any area in South Korea.
The Nodong missile is thought to have a range of around 1,300km and could potentially carry a nuclear warhead, though North Korea has not yet developed the technology to build a nuclear warhead for any of its missiles.
However, this missile is only thought to have been tested twice and it is not accurate. A March 2006 report, by the US Center for Non-proliferation Studies, said it had a 'circular error probable' of 2km to 4km, meaning that half of the missiles fired would fall outside a circle of that radius.
The Nodong has the range to strike most of Japan but not with any accuracy. If it were fired on a military target, its inaccuracy could lead to high levels of civilian casualties.
The Taepodong-1 is a two-stage missile comprising Nodong and Scud parts and can reach a distance of 2,900km.
With this range it would be able to reach US bases on Okinawa but the missile is thought to be even less accurate than the Nodong.
But the missile must be fired from a fixed location and has a long preparation time, meaning that potential launches could be detected.
North Korea tested a Taepodong-1 in August 1998, firing a missile over northern Japan.
The Taepodong-2 long-range missile is estimated to have a range of between 4,000km and 10,000km and, like the Taepodong-1, it requires a fixed launch site.
The first launch of the missile, in July 2006, appeared to be a failure after it crashed within seconds of launch - according to US sources.
If the missile was successfully launched, the increased power of the Taepodong-2 could put the UK, Australia, and even the US mid-west within range.
However, it could only carry a small payload to its maximum range and is not thought to be particularly accurate.
Defence experts say that the original Taepodong-2 is now being replaced by a newer model, which can have two or three stages giving it an extended range of up to 15,000km.
The three-stage Taepodong-2 was used in a failed attempt to launch a satellite in April 2009. The launch was widely condemned by the US and South Korea, among others, as cover for a long-range missile test.